Aristotle on Explanation

Book 1 chapter 1 of Parts of Animals provides an overview of Aristotle’s perspective on explanation in general. It is a nice synthetic text that brings together many of Aristotle’s core concerns, and shows his vision of how natural science ought to fit in with broader philosophy.

He begins by distinguishing between mere acquaintance with an area of study and being educated in it. “For an educated [person] should be able to form a fair judgment as to the goodness or badness of an exposition” (Complete Works, Barnes ed., vol. 1, p. 994). This seems to apply to any subject whatsoever.

Next he raises the more specific question of method. “It is plain then that, in the science which inquires into nature, there must be certain canons, by reference to which a hearer shall be able to criticize the method of a professed exposition, quite independently of the question whether the statements made be true or false” (ibid).

Continuing to emphasize the critical thinking that is the mark of an educated person, he makes it explicit that some of the most important questions about a subject are what I would call second-order questions, having to do with how we ought to approach the matter at hand. The educated person will give due emphasis to these, rather than naively rushing to deliver judgments on questions of fact.

“Ought we, for example (to give an illustration of what I mean) to begin by discussing each separate substance — man, lion, ox, and the like — taking each kind in hand independently of the rest, or ought we rather to lay down the attributes which they have in common in virtue of some common element of their nature? For genera that are quite distinct present many identical phenomena, sleep, for instance, respiration, growth, decay, death, and other similar affections and conditions…. Now it is plain that if we deal with each species independently of the rest, we shall frequently be obliged to repeat ourselves over and over again; for horse and dog and man present every one of the phenomena just enumerated” (ibid).

The educated person looks for explanations, not just facts or correspondences. The specific “dogginess” of a dog, for example, does not explain its sleeping, breathing, and so on. Instead these activities, which it shares with many other animals, are explained by natures common to all of them.

Further, the kind of method Aristotle commends to us is not a matter of following recipes by rote. Instead, it is a thinking approach that involves persistently following the thread of explanations wherever it leads.

“So also there is a like uncertainty as to another point now to be mentioned. Ought the student of nature follow the plan adopted by the mathematicians in their astronomical demonstrations, and after considering the phenomena presented by animals, and their several parts, proceed subsequently to treat of the causes and the reason why; or ought he to follow some other method? Furthermore, the causes concerned in natural generation are, as we see, more than one. There is the cause for the sake of which, and the cause whence the beginning of motion comes. Now we must decide which of these two causes comes first, which second. Plainly, however, that cause is the first which we call that for the sake of which. For this is the account of the thing, and the account forms the starting-point, alike in the works of art and in works of nature. For the doctor and the builder define health or house, either by the intellect or by perception, and then proceed to give the accounts and the causes of each of the things they do and of why they should do it thus” (p. 995).

He raises the question of which kind of cause comes first, because he wants to suggest a different answer from that of the pre-Socratic “physicists” who attempted to explain everything by properties of different kinds of matter. Elsewhere he says that Plato and the atomist Democritus (whose writings are lost) did better than others at following the thread of explanation, but he considers the elaborated account of ends or “that for the sake of which” to be one of his own most important contributions.

Notably he only mentions two kinds of cause here, rather than the classic four. Similarly, there are passages in other texts where he lists a different number of categories than the canonical ten from the Categories. Later authors often viewed things like causes and categories in a reified, univocal way, as susceptible to exact enumeration. But for Aristotle, these are abstractions from a concrete reality that comes first, to be wielded in a context-sensitive way, so the canonical enumerations are not absolute.

Aristotle’s understanding of the “beginning of motion” is different from that promoted by early modern physics. Conventionally in the reading of Aristotle, the “beginning of motion” is associated with the efficient cause, and these two terms are understood in a somewhat circular way, which is really informed by some broadly intuitive sense of what a “beginning” of motion is. Early modern writers assumed that this “beginning” must be some kind of immediate impulse or force. Aquinas associated it with God’s act of creation and with the free acts of created beings. For Aristotle himself it is neither of these.

My best reading of efficient cause is that it is the means by which an end is realized. In many cases the end is realized not by just one means but by a hierarchy of means (e.g., art of building, carpenter, carpenter’s hammer, hammer’s blow). Aristotle and the scholastics emphasized the top of such hierarchies (e.g., the art of building for Aristotle; God or some metaphysical principle for the scholastics), whereas the early moderns emphasized the bottom (e.g., the hammer’s blow), akin to the proximate cause of concern to liability lawyers. For Aristotle, the art of building and not the hammer’s blow is the true “beginning” of the motion of house construction, because it provides the guiding thread of explanation for the whole process of building the house. But even the art of building is still just a means that gets its meaning from the reasons why we would want to build a house in the first place.

He continues, “Now in the works of nature the good and that for the sake of which is still more dominant than in works of art, nor is necessity a factor with the same significance in them all; though almost all writers try to refer their accounts to this, failing to distinguish the several ways in which necessity is spoken of. For there is absolute necessity, manifested in eternal phenomena; and there is hypothetical necessity, manifested in everything that is generated as in everything that is produced by art, be it a house or what it may. For if a house or other such final object is to be realized, it is necessary that first this and then that shall be produced and set in motion, and so on in continuous succession, until the end is reached, for the sake of which each prior thing is produced and exists. So also is it with the productions of nature. The mode of necessity, however, and the mode of demonstration are different in natural science from what they are in the theoretical sciences [e.g., mathematics]…. For in the latter the starting-point is that which is; in the former that which is to be. For since health, or a man, is of such and such a character, it is necessary for this or that to exist or be produced; it is not the case that, since this or that exists or has been produced, that of necessity exists or will exist. Nor is it possible to trace back the necessity of demonstrations of this sort to a starting-point, of which you can say that, since this exists, that exists [as one might do in mathematics]” (ibid).

In Aristotle’s usage, “nature” applies to terrestrial things that are observably subject to generation and corruption. He earlier referred to astronomical phenomena like the apparent motions of the stars and planets as “eternal” because on a human scale of time, these are not observably subject to generation and corruption. For Aristotle, absolute necessity could only apply to things that are absolutely unchanging. We may have a different perspective on astronomy, but that does not affect the logical distinction Aristotle is making. His key point here is that things subject to generation are not subject to absolute necessity. Leibniz took this a step further and argued that hypothetical necessity is the only kind there is. Kant, in arguing that hypothetical and disjunctive judgment (“if A then B” and “not both A and B“) are more fundamental than categorical judgment (“A is B“), made a related move.

Hypothetical necessity has a particular form that is worth noting. As Aristotle points out in the quote above, under hypothetical necessity “it is not the case that, since this or that exists or has been produced, that of necessity exists or will exist”. To give a positive example, hypothetical necessity says that to continue living, we must eat. But it does not in any way dictate a particular series of motions that is the only way this can be accomplished, let alone the whole series of eating-related actions throughout one’s life. Neither does it dictate that we will eat in any particular instance.

How we meet a particular need is up to us. The reality of this flexibility built into nature is all we need to explain freedom of action. Humans can also affirmatively embrace commitments and act on them; that too is up to us. Freedom is not an arbitrary or supernatural power; it simply consists in the fact that nature is flexible, and many things are up to us.

Aristotle contrasts the way a thing is naturally generated with the way it is. “The best course appears to be that we follow the method already mentioned — begin with the phenomena presented by each group of animals, and, when this is done, proceed afterwards to state the causes of those phenomena — in the case of generation too. For in house building too, these things come about because the form of the house is such and such, rather than its being the case that the house is such and such because it comes about thus…. Art indeed consists in the account of the product without its matter. So too with chance products; for they are produced in the same way as products of art” (pp. 995-996).

“The fittest mode, then, of treatment is to say, a man has such and such parts, because the essence of man is such and such, and because they are necessarily conditions of his existence, or, if we cannot quite say this then the next thing to it, namely, that it is either quite impossible for a man to exist without them, or, at any rate, that it is good that they should be there. And this follows: because man is such and such the process of his development is necessarily such as it is; and therefore this part is formed first, that next; and after a like fashion should we explain the generation of all other works of nature” (p. 996).

This way of reasoning backwards from an essence to its prerequisites is complemented by the fact that for Aristotle (and Plato) essences themselves are a prime subject of investigation, and not something assumed. “Begin with the phenomena”, he says.

Many 20th century philosophers have objected to presumptuous talk about the “essence of man”, and to any explanation in terms of essence. But these objections presuppose that the essence is something assumed, rather than being an object of investigation as it clearly was for Plato and Aristotle. Here also it is needful to distinguish between what we might call the distinguishing essence of humanity used to pick out humans — e.g., “rational/talking animal” — and what Leibniz later called the complete essence of each individual. Clearly also, the parts of the human body do not follow directly from “rational/talking animal”, but from many other attributes “presented in the phenomena”. It turns out that humans share these attributes with other animals, and they can therefore be conceptualized as attributes of common genera to which we and those other animals belong.

Because essences themselves are a prime subject of investigation and are ultimately inferred from phenomena, the kind of teleological reasoning Aristotle recommends always has a contingent character, which is how it naturally accounts for what the moderns call freedom. This contingency is built into in the “hypothetical” character of hypothetical necessity.

“Does, then, configuration and color constitute the essence of the various animals and their several parts? For if so, what Democritus says will be correct…. And yet a dead body has exactly the same configuration as a living one; but for all that it is not a man. So also no hand of bronze or wood or constituted in any but the appropriate way can possibly be a hand in more than name. For like a physician in a painting, or like a flute in a sculpture, it will be unable to perform its function” (p. 997).

Aristotle was the historic pioneer of “functional” explanation. Here he insists that the essences of living beings and their parts must be understood in terms of their characteristic activities. This development for the sake of biology parallels the deeper development of the meaning of “substance” in the Metaphysics as “what it was to be” a thing, and as actuality and potentiality.

“If now the form of the living being is the soul, or part of the soul, or something that without the soul cannot exist; as would seem to be the case, seeing at any rate that when the soul departs, what is left is no longer an animal, and that none of the parts remain what they were before, excepting in mere configuration, like the animals that in the fable are turned into stone; if, I say, this is so, then it will come within the province of the natural scientist to inform himself concerning the soul, and to treat of it, either in its entirety, or, at any rate, of that part of it which constitutes the essential character of an animal; and it will be his duty to say what a soul or this part of a soul is” (ibid).

Here it is important that we consider soul in the “phenomena first” way that Aristotle develops it.

“What has been said suggests the question, whether it is the whole soul or only some part of it, the consideration of which comes within the province of natural science. Now if it be of the whole soul that this should treat, then there is no place for any philosophy beside it…. But perhaps it is not the whole soul, nor all of its parts collectively, that constitutes the source of motion; but there may be one part, identical with that in plants, which is the source of growth, another, namely the sensory part, which is the source of change of quality, while still another, and this is not the intellectual part, is the source of locomotion. For other animals than man have the power of locomotion, but in none but him is there intellect. Thus it is plain that it is not of the whole soul that we have to treat. For it is not the whole soul that constitutes the animal nature, but only some part or parts of it” (p. 998).

Aristotle’s opposition to treating the soul as a single lump reflects his overall functional, activity-oriented, and phenomena-first approach.

“Again, whenever there is plainly some final end, to which a motion tends should nothing stand in its way, we always say that the one is for the sake of the other; and from this it is evident that there must be something of the kind, corresponding to what we call nature” (ibid).

Overall teleology always has to do with tendencies, not absolute determinations. He begins to wrap up this introduction by giving another example of the hypothetical necessity whose concept he pioneered.

“For if a piece of wood is to be split with an axe, the axe must of necessity be hard; and, if hard, must of necessity be made of bronze or iron. Now in exactly the same way the body, since it is an instrument — for both the body as a whole and its several parts individually are for the sake of something — if it is to do its work, must of necessity be of such and such a character, and made of such and such materials.”

“It is plain then that there are two modes of causation, and that both of these must, so far as possible, be taken into account, or at any rate an attempt must be made to include them both; and that those who fail in this tell us in reality nothing about nature” (p. 999).

Again, the two modes here are “that for the sake of which” and the phenomena associated with generation. Considering either of these in isolation yields an incomplete understanding, as we see respectively in bad scholasticism and bad empiricism.

“The reason why our predecessors failed to hit on this method of treatment was, that they were not in possession of the notion of essence, nor of any definition of substance. The first who came near it was Democritus, and he was far from adopting it as a necessary method in natural science, but was merely brought to it by constraint of facts. In the time of Socrates a nearer approach was made to the method. But at this period men gave up inquiring into nature, and philosophers diverted their attention to political science and to the virtues that benefit mankind” (ibid).

Socrates and Plato initially pioneered the notion of “that for the sake of which”, but in turning away from the phenomena of generation and becoming, they gave it a somewhat one-sided character.

The subtle way in which Aristotle wields the concept of essence avoids treating it as an absolute, or as something strictly univocal. In any given context, there is a clear relative distinction between essence and accident, but the distinction is not the same across all contexts. Hypothetical necessity provides the mechanism by which what is “accident” at one level of analysis can be incorporated into “essence” at another level. (See also Hermeneutic Biology?; Aristotelian Causes; Secondary Causes; Aristotle’s Critique of Dichotomy; Classification.)

Aristotle’s Critique of Dichotomy

Chapter 3 of the extraordinarily rich book 1 of Aristotle’s Parts of Animals contains a strong critique of the notion of classification by dichotomy, with implications reaching far beyond its original context. The idea that he criticizes is Platonic division into As and not-As, which is intended to result in a binary tree structure (i.e., a tree-shape in which all the branches are binary).

Platonic division was perhaps inspired by the two-sided character of Platonic dialectic, which was concerned with impartially examining the implications of both sides of some disputable question, particularly in the form of arguments for and against some thesis or other. Aristotle’s own dialectic has a more general form that is not bound to arguments for and against, but rather is simply concerned with an impartial examination of the consequences of hypotheses.

But in any case, classification in a world is a different problem from that of impartially examining a single hypothesis.

Ignoring Aristotle’s lesson, and strongly influenced by the more general impoverished notion of logical judgment as grammatical predication, early modern writers on natural history attempted to follow an a priori theory of univocal classification. But for Aristotle, there is no a priori theory of classification. Instead, the starting point is what Kant would call the implicitly schematized manifold of a concrete world.

Aristotle points out that if classification were reducible to the assignment of predicates, then to consistently classify a world or any given collection, there would have to be some one order in which we divide things by one predicate, then another, and so on. By examples he illustrates the fact that by this method, it is impossible to arrive at the division of animal species that we recognize in nature.

He also makes the more general argument that half of the classifying terms in any classification by sequential predication will be negatives, and that negative terms cannot be properly subdivided.

“Again, privative [negative] terms inevitably form one branch of dichotomous division, as we see in the proposed dichotomies. But privative terms in their character of privatives admit of no subdivision. For there can be no specific forms of a negation, of Featherless for instance or of Footless, as there are of Feathered and of Footed. Yet a generic differentia must be subdivisible; for otherwise what is there that makes it generic rather than specific? There are to be found generic, that is to say specifically subdivisible, differentiae; Feathered for instance and Footed. For feathers are divisible into Barbed and Unbarbed, and feet into Manycleft, and Twocleft, like those of animals with bifid hoofs, and Uncleft or Undivided, like those of animals with solid hoofs. Now even with the differentiae capable of this specific subdivision it is difficult enough so to make the classification that each animal shall be comprehended in some one subdivision and not in more than one (e.g. winged and wingless; for some are both — e.g. ants, glowworms, and some others); but far more difficult, impossible, is it to do this, if we start with a dichotomy into two contradictories. For each differentia must be presented by some species. There must be some species, therefore, under the privative heading. Now specifically distinct animals cannot present in their substance a common undifferentiated element, but any apparently common element must really be differentiated. (Bird and Man for instance are both Two-footed, but their two-footedness is diverse and differentiated. And if they are sanguineous they must have some difference in their blood, if blood is part of their substance.) From this it follows that one differentia will belong to two species; and if that is so, it is plain that a privative cannot be a differentia.” (Complete Works, Barnes ed., vol. 1, p. 1000).

Aristotle’s positive conclusion is as as follows:

“We must attempt to recognize the natural groups, following the indications afforded by the instincts of mankind, which led them for instance to form the class of Birds and the class of Fishes, each of which groups combines a multitude of differentiae, and is not defined by a single one as in dichotomy. The method of dichotomy is either impossible (for it would put a single group under different divisions or contrary groups under the same division), or it only furnishes a single differentia for each species…. As we said then, we must define at the outset by a multiplicity of differentiae. If we do so, privative terms will be available, which are unavailable to the dichotomist” (pp. 1001-1002, emphasis added).

This is consistent with Plato’s more general advice that classifiers, like butchers, should “cut at the joints”, i.e., look for natural distinctions rather than imposing artificial ones. Dipping back again to the negative argument, Aristotle adds:

“Now if man was nothing more than a Cleft-footed animal, this single differentia would duly represent his essence. But seeing that this is not the case, more differentiae than this one will necessarily be required to define him; and these cannot come under one division; for each single branch of a dichotomy end in a single differentia, and cannot possibly include several differentiae belonging to one and the same animal.”

“It is impossible then to reach any of the ultimate animal forms by dichotomous division” (p. 1002; see also Classification; Hermeneutic Biology?.)

Passive Synthesis: Conclusion

Husserl’s initial discussion of associative synthesis seems to me to be the climax of his lectures on passive synthesis, resulting in a great simultaneous genesis of the experience of time, self, world, and objects. He had indicated that the next frontier would involve taking more account of the content of things as opposed to the mere genesis of their identities, but I confess I found the follow-through disappointing. Here he follows conventional treatments of association that emphasize similarity as the main basis of particular associations. In hindsight, I’m inclined to doubt whether association really ought to be the main theme governing what I just called the great simultaneous genesis.

There is a discussion of affection that I also found disappointing. Curiously, it is separated from another later section that touches on feeling. Feeling he treats only as a function of the ego, outside the scope of “passive” synthesis. I see feeling as deeply bound up with the imagination and spontaneous belief involved in preconscious synthesis. I would prefer to see the ego treated as a function of feeling, rather than vice versa.

I do think he succeeds in developing the overall notion of preconscious synthesis in a somewhat more concrete way than Kant, who already greatly fleshes out this territory in comparison with Aristotle’s brilliant but obscure hints that I take to imply a kind of synthesis at work in the “common sense” and “inner sense”. As I mentioned in the last post, the very fact that Husserl here considers subjectivity as something constituted and not only as something constituting other things is also of great importance.

I was disappointed that so much of the discussion was limited to beliefs arising out of sense perception. In his early Logical Investigations, Husserl was engaged with a much broader inquiry into meaning as something not merely subjective or psychological. At the level of what he calls passive synthesis, I would hope to see much more about the linguistic side of our being.

When Husserl was working, Sellars and Brandom had not yet developed the rediscovery of concrete meaning-based material inference. Just as much of our immersion in language is at a preconscious level, I think we make many material inferences at a preconscious level, and this provides a far richer basis for the shaping of experience than similarity-based association. (See also Phenomenological Reduction?.)

Cause

Aristotle flourished before the great flowering of Greek mathematics that gave us Euclid, Ptolemy, Apollonius, and Aristarchus. In his day, mathematics amounted to just arithmetic and simple geometry. In spite of the famous Pythagorean theorem that the square constructed from the hypotenuse of a right triangle is equal in area to the sum of the squares constructed from the other two sides, the historic reality of the Pythagorean movement had more to do with number mysticism, other superstitions, and curious injunctions like “don’t eat beans” than it did with real mathematics.

I think Aristotle was entirely right to conclude that arithmetic and simple geometry were of little use for explaining change in the natural world. I’ve characterized his physics as grounded in a kind of semantic inquiry that Aristotle pioneered. We are not used to thinking about science this way, as fundamentally involved with a very human inquiry about the meaning of experience in life, rather than predictive calculation. For Aristotle, the gap between natural science and thoughtful reflection about ordinary experience was much smaller than it is for us.

Aristotle invented the notion of cause as a semantic tool for expressing the reasons why changes occur. Aristotle’s notion is far more abstract than the metaphor of impulse or something pushing on something else that guided early modern mechanism. Even though the notion of cause was originally developed in a text included in Aristotle’s Physics, the “semantic” grounding of Aristotelian physics places it closer to logic than to modern physical inquiries.

I think the discussion of the kinds of causes could equally well have been grouped among his “logical” works. In fact, the form in which we have Aristotle’s works today is the result of the efforts of multiple ancient editors, who sometimes stitched together separate manuscripts, so there is room for a legitimate question whether the discussion of causes was originally a separate treatise. We tend to assume that there must be something inherently “physical” about the discussion of causes, but this is ultimately due to a circular argument from the fact that the more detailed version of it came down to us as part of the Physics (there is another, briefer one that came down to us as part of the Metaphysics).

Since Hume and especially since the later 19th century, many authors have debated about the role of causes in science. Bertrand Russell argued in the early 20th century that modern science does not in fact depend on what I have called the modern notion of cause.

More recently, Robert Brandom has argued that the purpose of logic is “to make explicit the inferential relations that articulate the semantic contents of the concepts expressed by the use of ordinary, nonlogical vocabulary”. I see Aristotelian causes in this light.

I want to recommend a return to a notion of causes in general as explanatory reasons rather than things that exert force. This can include all the mathematics used in modern science, as well as a broader range of reasons relevant to life. (See also Aristotelian Causes; Mechanical Metaphors; Causes: Real, Heuristic?; Effective vs “Driving”; Secondary Causes.)

Spontaneity

Spontaneity has a technical meaning in Kant and Husserl that is at odds with common usage. In ordinary speech, we are said to do something “spontaneously” when we do it on the spur of the moment, without a previous plan. But Kant and Husserl call everything guided by reason “spontaneous”, even though reason is involved with conscious deliberation and thinking things through.

According to an older usage, things in nature were said by some to occur “spontaneously” when they had no discernible cause. In the scholastic tradition, others argued that “nothing comes from nothing”, and rejected the assumption that things with no discernible cause really happen without a cause, as was purported to occur in what was called “spontaneous generation”.

Leibniz embraced and codified the “nothing from nothing” argument as the principle of sufficient reason. The principle of sufficient reason does not itself imply the kind of particular providence associated with the popular expression “everything happens for a reason”. It just says that everything has some kind of reasonable explanation, not that what we subjectively perceive as cosmic injustice is part of a divine plan, even though Leibniz separately argued for that as well.

Of course, it matters a lot what kinds of causes or reasonable explanations we recognize. In Leibniz’s time, the notion of cause had already been greatly contracted by early modern writers, who further transformed the late scholastic notion of efficient cause in a mechanistic direction, while accentuating the late scholastic tendency to reduce all other causes to efficient causes. Leibniz himself recommended the use of only mechanistic explanations in natural science, but did not see natural science as all-encompassing, and defended the use of teleological explanation in broader philosophy. He compensated for the narrowness of mechanistic causality by speaking of sufficient reason rather than sufficient cause, and kept a place for form and ends as reasons.

Kant ultimately also defended a kind of teleology, especially in biology and in his account of beauty, but he was much more reserved about using it in general explanation than Leibniz, due to his scruples about grounding all “theoretical” explanation in experience. However, he assigned all ethical matters to a separate “practical” domain, which he wanted to exempt from the kind of narrow causal explanation that he considered the norm for physics, and he argued that for us humans, “practical” reason is more fundamental.

Human action for Kant belongs to the practical domain, which he famously argued is governed by “spontaneity” and “freedom”. I now think “spontaneous” and “free” for Kant simply mean not subject to mechanistic explanation. Thus insofar as we are positively motivated by moral imperatives or values, he would say we act spontaneously and freely. I think he also believed that all human thinking is ultimately motivated by ultimate ends, and therefore called it spontaneous and free.

Kant confused generations of scholars by borrowing voluntaristic rhetoric, which he did with the aim of emphasizing that human thought and action are not reducible to mechanistic physics. But freedom and spontaneity in Kant do not mean arbitrariness, as they effectively do for defenders of voluntarism. Rather, they are meant to allow room for positive motivation by moral imperatives or values.

Another confusing move Kant made was to argue for a special “causality of freedom” that he never explained adequately. Due to its contrast with physical causality, it sounded at times like a kind of supernatural break in the natural order he otherwise recognized. Many commentators thought Kant contradicted himself in arguing both that the natural order is self-contained and that there is a separate causality of freedom. I think these problems are ultimately explained by the narrowness of the mechanical concept of causality in nature. The “causality of freedom”, I want to say, simply means motivation by moral imperatives or values rather than by impulse. Kant considered impulse to be within the realm of natural-scientific causality, and therefore opposed it to spontaneity, whereas contemporary common usage associates “spontaneity” with acting on impulse.

(Aristotle, with his much broader notion of cause that essentially identifies causes with any kinds of “reasons why”, would treat values and moral imperatives as one kind of final causes, or what I have been calling “ends”.)

Husserl’s way of speaking about these matters is to contrast human motivation with causality. For him, “causality” is exclusively the causality of modern physical science, but human thought and action are to be explained by “motivation” rather than causality. Husserl’s use of “spontaneity” is related to that of Kant, and applies to everything that he explains in terms of motivation. (See also Kantian Freedom; Kantian Will; Allison on Kant on Freedom; Freedom Through Deliberation?.)

Imagination: Aristotle, Kant

In the glossary to his translation of Aristotle’s On the Soul, Joe Sachs nicely summarizes the various roles of phantasia or “imagination” in Aristotle:

“A power of the soul that perceives appearances when perceptible things are absent and thinks without distinguishing universals (429a 4-8, 434a 5-11). The imagination is identified in On Memory and Recollection as the primary perceptive power of the soul (449b 31 – 450a 15). Thus, many activities discovered in On the Soul may be collected and attributed to the imagination, such as perceiving common and incidental objects of the senses, being aware that we are perceiving, discriminating among the objects of the different senses (425a 14 – b 25), distinguishing flesh or water (429b 10-18), and perceiving time (433b 7). Also, implicit within the power of imagination to behold images (phantasmata), there must be imagination in a second sense, eikasia, by which we can see an image as an image (eikon) or likeness (On Memory and Recollection 450b 12-27)” (pp. 194-195; citations in original).

In the above, I would particularly highlight “thinking without distinguishing universals” and “being aware that we are perceiving”. Imagination — and not intellect, for instance — seems to me to be the primary source suggested in Aristotle for what we, following Locke, call “consciousness”. Also noteworthy is language suggestive of what Kant would later call synthesis.

The vital implication here is that the closest analogue of “consciousness” in Aristotle comes into being not as a transparent medium of representation, but rather as a shifting collection of concrete forms in imagination. Further, the forms we experience are not just passively received, but actively organized and discriminated at a pre-conscious level. Thus when Aristotle says — as he also does — that, e.g., the eye is essentially passive in receiving forms as differentiations in received light — this latter is intended at a purely physical level, and is far from providing a full account of, e.g., visual perception by a human.

Prior to Descartes’ confabulation of scholastic “cogitation” and “intellection”, concrete human psychic activity or “cogitation” was generally recognized as having its roots in imagination. Intellection was understood to have a more specialized role, focused on the constitution of universals. However, attempts to reconcile Aristotle with Plotinus and Proclus in the Arabic tradition, and then with Augustine and pseudo-Dionysius in the Latin tradition, provided a background that was ultimately very supportive toward Aquinas’ strong claim that intellect must after all be understood as the leading part of the individual human soul, morally responsible for all its concrete thoughts and actions. This made it far more plausible for Descartes to take the further step — which Locke followed — of simply identifying cogitation and intellection. The self-transparency of the cogito in Descartes and of consciousness in Locke, respectively — along with their identification with intellection — served to marginalize the role of forms in imagination in their conceptions of “mind”.

A very important feature of Kant’s work that is relatively little appreciated is that he restored a central role for “imagination” in philosophical psychology and anthropology. For Kant, humans can have neither direct knowledge of empirical facts or objects, nor any knowledge of transcendent realities. All intellection and knowledge are discursive, as I think Aristotle would have agreed. We have immediate though “blind” intuition of a sensible manifold, but intellectual intuition is an oxymoron, because intellection is inherently discursive. And in between the synthesis of initial sensory apprehension in intuition and the synthesis of recognition in the concept (Kant’s equivalent for intellection) comes a crucial synthesis of reproduction in imagination. Though his terminology is quite different, Kant not only recovers but even expands upon the role that imagination played in Aristotle.

In Kant and the Capacity to Judge, Beatrice Longuenesse carefully develops what Kant says about imagination in the Critique of Pure Reason. This is a major dimension of her book, so I can only give a flavor of it here.

“The imagination ‘in which’ there is reproduction is not the imagination as a faculty or power (Einbildungskraft), but the representation produced by this faculty (Einbildung)” (p. 35). Though Kant uses the terminology of representation, this effectively refers to the same forms in imagination that Aristotle emphasized.

“[Kant] shows that these acts of combination can contribute to the cognition of a phaenomenon, an object distinct from the ‘indeterminate object of empirical intuition’ (Erscheinung [or mere appearance]), only if they all belong to one and the same act of synthesis of the spatiotemporal manifold. The form of this act is determined a priori by the nature of our mind, and its outcome is threefold: the manifold of intuition represented ‘as’ manifold, the representation of imagination (Einbildung) emerging from empirical associations, and finally the universal representation or concept, under which particular representations are subsumed. This act is that very act of synthesis which Kant, in section 10, attributes to the imagination, in the A Deduction [of the categories] more precisely to transcendental imagination, and which in the B Deduction he calls synthesis speciosa, figurative synthesis” (pp. 35-36).

As usual in Kant, “transcendental” means not metaphysical, but simply constitutive in a way that is not reducible to empirical events. Longuenesse points out that imagination in Kant is not merely reproductive, but also productive. In any case, for Kant not only the logical “matter” but also the elaborated form of our fully constituted experience owes a great deal to imagination, and a recognition of this — as opposed to the assumption of a putative transparency of consciousness — is fundamental to the “Critical” attitude Kant aimed to promote. Here I am using “form” in a sense more Aristotelian than Kantian. (See also Capacity to Judge; Figurative Synthesis; Imagination, Emotion, Opinion; Animal Imagination; Imagination; Four Layers of Being Human.)

McDowell on the Space of Reasons

John McDowell’s paper “Sellars and the Space of Reasons” (2018) provides a useful discussion of this concept. Unlike Brandom, who aims to complete Sellars’ break with empiricism, McDowell ultimately wants to defend “a non-traditional empiricism, uncontaminated by the Myth of the Given” (p. 1).

McDowell begins by quoting Sellars: “in characterizing an episode or a state as that of knowing, we are not giving an empirical description of that episode or state; we are placing it in the logical space of reasons, of justifying and being able to justify what one says” (ibid; emphasis added).

For Sellars, to speak of states of knowing is to talk about “epistemic facts”. A bit later, McDowell says that Sellars’ epistemic facts also include judgments and uses of concepts that might not be considered knowledge. Not only beliefs but also desires end up as a kind of epistemic facts. McDowell uses this to argue that the space of reasons is a version of the concept of knowledge as justified true belief. I want to resist this last claim.

McDowell points out that knowledge for Sellars has a normative character. Sellars also regards the foundationalist claim that epistemic facts can be explained entirely in terms of non-epistemic facts (physiology of perception and so on) as of a piece with the naturalistic fallacy in ethics.

McDowell cites Donald Davidson’s contrast between space-of-reasons intelligibility and the kind of regularity-based intelligibility that applies to a discipline like physics, but does not want to assume there is a single model for all non-space-of-reasons intelligibility.

He notes that Sellars contrasts placing something in the space of reasons with empirical description, but wants to weaken that distinction, allowing epistemic facts to be grounded in experience, and to be themselves subject to empirical description. “Epistemic facts are facts too” (p. 5). I prefer going the other direction, and saying empirical descriptions are judgments too.

The space of reasons is only occupied by speakers. Sellars is quoted saying, “all awareness of sorts, resemblances, facts, etc., in short all awareness of abstract entities — indeed, all awareness even of particulars — is a linguistic affair” (p. 7, emphasis in original). “And when Sellars connects being appropriately positioned in the space of reasons with being able to justify what one says, that is not just a matter of singling out a particularly striking instance of having a justified belief, as if that idea could apply equally well to beings that cannot give linguistic expression to what they know” (ibid).

“‘Inner’ episodes with conceptual content are to be understood on the model of overt performances in which people, for instance, say that things are thus and so” (p. 8). “What Sellars proposes is that the concept of, for instance, perceptual awareness that things are thus and so should be understood on the model of the concept of, for instance, saying that things are thus and so” (p. 10). All good so far.

To be in the space of reasons, “the subject would need to be able to step back from the fact that it is inclined in a certain direction by the circumstance. It would need to be able to raise the question whether it should be so inclined” (pp. 10-11, emphasis in original). But McDowell says — and I agree — that this is without prejudice as to whether there is still a kind of kinship between taking reasons as reasons, on the one hand, and the purposeful behaviors of animals, on the other.

McDowell acknowledges that the idea that epistemic facts can only be justified by other epistemic facts is easy to apply to inferential knowledge, but rather harder to apply to the “observational knowledge” that he claims should also be included in the space of reasons. For McDowell, observational knowledge is subject to a kind of justification by other facts.

McDowell and Brandom both recognize something called “observational knowledge”, but Brandom thinks that it necessarily involves appeal to claimed non-epistemic facts, whereas McDowell wants to broaden the concept of epistemic facts enough to be able to say that observational knowledge can be justified by appealing only to epistemic facts. I would prefer to say, observational judgments are subject to a kind of tentative justification by other judgments.

McDowell says that acquiring knowledge noninferentially is also an exercise of conceptual capacities. This clearly implies a noninferential conception of the conceptual, and seems to me to presuppose a representationalist one instead. This has huge consequences.

He says that the space of reasons must include noninferential relations of justification, which work by appeal to additional facts rather by inference. But where did those facts come from? In light of Kant, I would say that we rational animals never have direct access to facts that just are what they are. Rather, if we are being careful, we should recognize that we can only consider claims and judgments of fact, which may be relatively well-founded or not. But appeal to claims of fact for justification is just passing the buck. Claims of any sort always require justification of their own.

As an example, McDowell discusses claims to know that something is green in color. As non-inferential justification in this context, he says one might say that “This is a good light for telling the colours of things by looking” (p. 18). That is fine as a criterion for relatively well-founded belief, but that is all it is.

A bit later, he adds, “I can tell a green thing when I see one, at least in a good light, viewed head-on, and so forth. A serviceable gloss on that remark is to say that if I claim, in suitable circumstances, that something is green, then it is” (p. 19).

This is to explicitly endorse self-certification of one’s authority. It is therefore ultimately to allow the claim, it’s true because I said so. I think it was a rejection on principle of this kind of self-certification that led Plato to sharply distinguish knowledge from belief.

As Aristotle pointed out in discussing the relation between what he respectively called “demonstration” and “dialectic”, we can apply the same kinds of inference both to things we take as true and to things we are examining hypothetically. We can make only hypothetical inferences (if A, then B) from claims or judgments of A; we can only legitimately make categorical inferences (A, therefore B) from full-fledged knowledge of A — which, to be such, must at minimum not beg the question or pass the buck of justification.

The great majority of our real-world reasoning is ultimately hypothetical rather than categorical, even though we routinely act as if it were categorical. One of Kant’s great contributions was to point out that — contrary to scholastic and early modern tradition — hypothetical judgement is a much better model of judgment in general than categorical judgment is. The general form of judgment is conditional, and not absolute.

I think it’s fine to include beliefs, opinions, and judgments in the space of reasons as McDowell wants to do, provided we recognize their ultimately hypothetical and tentative character. But once we recognize the hypothetical and tentative character of beliefs, I think it follows that all relations within the space of reasons can be construed as inferential.

I don’t think contemporary science has much to do with so-called observational knowledge of the “it is green” variety, either. Rather, it has to do partly with applications of mathematics, and partly with well-controlled experiments, in which the detailed conditions of the controls are far more decisive than the observational component. The prejudice that simple categorical judgments like “it is green” have anything to do with science is a holdover from old foundationalist theories of sense data.

I would also contend that all putative non-space-of-reasons intelligibility ultimately depends on space-of-reasons intelligibility. (See also What We Saw.)

Logic for Expression

In recent times, Robert Brandom has pioneered the idea that the role of logic is primarily expressive. In his 2018 essay “From Logical Expressivism to Expressivist Logic”, he says this means its purpose is “to make explicit the inferential relations that articulate the semantic contents of the concepts expressed by the use of ordinary, nonlogical vocabulary” (p. 70).

In my humble opinion, this is what logic was really supposed to be about in Aristotle, but the tradition did not follow Aristotle. Aristotle insisted that logic is a “tool” not a science, but most later authors have assumed the contrary — that logic was the “science” of correct reasoning, or perhaps the science of consequence relations. Several scholars have nonetheless rediscovered the idea that the purpose of logical demonstration in Aristotle is not to prove truths, but to express reasoned arguments as clearly as possible.

Brandom says that “the task of logic is to provide mathematical tools for articulating the structure of reasoning” (p. 71). People were reasoning in ordinary life long before logic was invented, and continue to do so. But the immensely fertile further development of logic in the late 19th and early 20th centuries was mostly geared toward the formalization of mathematics. Reasoning in most specialized disciplines — such as the empirical sciences, medicine, and law — actually resembles reasoning in ordinary life more than it does specifically mathematical reasoning.

According to Brandom, “The normative center of reasoning is the practice of assessing reasons for and against conclusions. Reasons for conclusions are normatively governed by relations of consequence or implication. Reasons against conclusions are normatively governed by relations of incompatibility. These relations of implication and incompatibility, which constrain normative assessment of giving reasons for and against claims, amount to the first significant level of structure of the practice of giving reasons for and against claims.”

“These are, in the first instance, what Sellars called ‘material’ relations of implication and incompatibility. That is, they do not depend on the presence of logical vocabulary or concepts, but only on the contents of non- or prelogical concepts. According to semantic inferentialism, these are the relations that articulate the conceptual contents expressed by the prelogical vocabulary that plays an essential role in formulating the premises and conclusions of inferences” (pp. 71-72).

“Material” relations of consequence and incompatibility have a different structure from formal ones. Formal consequence is monotonic, which means that adding new premises does not change the consequences of existing premises. Formal contradiction is “explosive”, in the sense that any contradiction whatsoever makes it possible to “prove” anything whatsoever (both true statements and their negations), thereby invalidating the very applicability of proof. But as Brandom reminds us, “outside of mathematics, almost all our actual reasoning is defeasible” (p. 72). Material consequence is nonmonotonic, which means that adding new premises could change the consequences of existing ones. Material incompatibilities can often be “fixed” by adding new, specialized premises. (As I somewhere heard Aquinas was supposed to have said, “When faced with a contradiction, introduce a distinction”.)

Brandom notes that “Ceteris paribus [“other things being equal”] clauses do not magically turn nonmonotonic implications into monotonic ones. (The proper term for a Latin phrase whose recitation can do that is ‘magic spell’.) The expressive function characteristic of ceteris paribus clauses is rather explicitly to mark and acknowledge the defeasibility, hence nonmonotonicity, of an implication codified in a conditional, not to cure it by fiat” (p. 73).

“There is no good reason to restrict the expressive ambitions with which we introduce logical vocabulary to making explicit the rare material relations of implication and incompatibility that are monotonic. Comfort with such impoverished ambition is a historical artifact of the contingent origins of modern logic in logicist and formalist programs aimed at codifying specifically mathematical reasoning. It is to be explained by appeal to historical causes, not good philosophical reasons” (ibid). On the other hand, making things explicit should be conservative in the sense of not changing existing implications.

“…[W]e should not emulate the drunk who looks for his lost keys under the lamp-post rather than where he actually dropped them, just because the light is better there. We should look to shine light where we need it most” (ibid).

For relations of material consequence, the classical principle of “explosion” should be replaced with the weaker one that “if [something] is not only materially incoherent (in the sense of explicitly containing incompatible premises) but persistently so, that is incurably, indefeasibly
incoherent, in that all of its supersets are also incoherent, then it implies everything” (p. 77).

“The logic of nonmonotonic consequence relations is itself monotonic. Yet it can express, in the logically extended object language, the nonmonotonic relations of implication and incompatibility that structure both the material, prelogical base language, and the logically compound sentences formed from them” (p. 82).

Material consequence relations themselves may or may not be monotonic. Instead of requiring monotonicity globally, it can be declared locally by means of a modal operator. “Logical expressivists want to introduce logical vocabulary that explicitly marks the difference between those implications and incompatibilities that are persistent under the addition of arbitrary auxiliary hypotheses or collateral commitments, and those that are not. Such vocabulary lets us draw explicit boundaries around the islands of monotonicity to be found surrounded by the sea of nonmonotonic material consequences and incompatibilities” (p. 83).

Ranges of subjunctive robustness can also be explicitly declared. “The underlying thought is that the most important information about a material implication is not whether or not it is monotonic — though that is something we indeed might want to know. It is rather under what circumstances it is robust and under what collateral circumstances it would be defeated” (p. 85).

“The space of material implications that articulates the contents of the nonlogical concepts those implications essentially depend upon has an intricate localized structure of subjunctive robustness and defeasibility. That is the structure we want our logical expressive tools to help us characterize. It is obscured by commitment to global structural monotonicity—however appropriate such a commitment might be for purely logical relations of implication and incompatibility” (pp. 85-86).

“Logic does not supply a canon of right reasoning, nor a standard of rationality. Rather, logic takes its place in the context of an already up-and-running rational enterprise of making claims and giving reasons for and against claims. Logic provides a distinctive organ of self-consciousness for such a rational practice. It provides expressive tools for talking and thinking, making claims, about the relations of implication and incompatibility that structure the giving of reasons for and against claims” (p. 87).

Efficient vs Proximate Causes

Joe Sachs links the notion of proximate cause to what I have called the modern sense of “efficient cause”.

The brief passage in Aristotle’s Metaphysics that seems to have primarily driven scholastic discussions of efficient causes reads “In yet another [way], [cause] is that from which the first beginning of change or rest is, as the legislator is a cause, or the father of a child, or generally the maker of what is made, or whatever makes a changing thing change” (Book V chapter 2, 1013a30-33, Sachs translation, p. 78).

Sachs’ footnote to this passage says “This is sometimes mistakenly called the efficient cause. Aristotle never describes it in such a way, and we generally intend by the phrase [efficient cause] the proximate cause, the last event that issues in the effect. Aristotle always means instead the origin of the motion, when it happens to be outside the moving thing. It is only in a derivative sense that he will speak of a push or a bump as being a cause at all, since, as he says at 1013a16 above, all causes are sources” (p. 78n).

When he says “Aristotle never describes it this way”, I think he means that “efficient cause” is yet another Latin-derived standard translation that has quite different connotations from the original Greek.

The excellent Stanford Encyclopedia of Philosophy article “Aristotle on Causality” reconciles the brief reference in the Metaphysics with Aristotle’s much more detailed discussion in the Physics. This is worthy of an unusually long quotation:

“[A]n adequate explanation of the production of a [bronze] statue requires also a reference to the efficient cause or the principle that produces the statue. For Aristotle, this is the art of bronze-casting the statue….”

“This result is mildly surprising and requires a few words of elaboration. There is no doubt that the art of bronze-casting resides in an individual artisan who is responsible for the production of the statue. According to Aristotle, however, all the artisan does in the production of the statue is the manifestation of specific knowledge. This knowledge, not the artisan who has mastered it, is the salient explanatory factor that one should pick as the most accurate specification of the efficient cause (Phys. 195b21-25). By picking the art, not the artisan, Aristotle is not just trying to provide an explanation of the production of the statue that is not dependent upon the desires, beliefs and intentions of the individual artisan; he is trying to offer an entirely different type of explanation – namely, an explanation that does not make a reference (implicit or explicit) to these desires, beliefs and intentions. More directly, the art of bronze-casting the statue enters in the explanation as the efficient cause because it helps us to understand what it takes to produce the statue; that is to say, what steps are required to produce the statue. But can an explanation of this type be given without a reference to the final outcome of the production, the statue? The answer is emphatically “no”. A model is made for producing the statue. A mold is prepared for producing the statue. The bronze is melted and poured for producing the statue. Both the prior and the subsequent stage are for the sake of a certain end, the production of the statue. Clearly, the statue enters in the explanation of each step of the artistic production as the final cause or that for the sake of which everything in the production process is done.”

“In thinking about the four causes, we have come to understand that Aristotle offers a teleological explanation of the production of a bronze statue; that is to say, an explanation that makes a reference to the telos or end of the process. Moreover, a teleological explanation of the type sketched above does not crucially depend upon the application of psychological concepts such as desires, beliefs and intentions. This is important because artistic production provides Aristotle with a teleological model for the study of natural processes, whose explanation does not involve beliefs, desires, intentions or anything of this sort. Some have objected that Aristotle explains natural process on the basis of an inappropriately psychological teleological model; that is to say, a teleological model that involves a purposive agent who is somehow sensitive to the end. This objection can be met if the artistic model is understood in non-psychological terms. In other words, Aristotle does not psychologize nature because his study of the natural world is based on a teleological model that is consciously free from psychological factors….”

“One final clarification is in order. By insisting on the art of bronze-casting as the most accurate efficient cause of the production of the statue, Aristotle does not mean to preclude an appeal to the beliefs and desires of the individual artisan. On the contrary, there are cases where the individual realization of the art obviously enters in the explanation of the bronze statue. For example, one may be interested in a particular bronze statue because that statue is the great achievement of an artisan who has not only mastered the art but has also applied it with a distinctive style. In this case it is perfectly appropriate to make reference to the beliefs and desires of the artisan. Aristotle seems to make room for this case when he says that we should look “for general causes of general things and for particular causes of particular things” (Phys. 195b25-26). Note, however, that the idiosyncrasies that may be important in studying a particular bronze statue as the great achievement of an individual artisan may be extraneous to a more central (and more interesting) case. To understand why let us focus on the study of nature. When the student of nature is concerned with the explanation of a natural phenomenon like the formation of sharp teeth in the front and broad molars in the back of the mouth, the student of nature is concerned with what is typical about that phenomenon. In other words, the student of nature is expected to provide an explanation of why certain animals typically have a certain dental arrangement.”

“Moral”, “Judgment”

Hegel regarded a forgiving stance as transcending what he called the Moral World-View. Other writers have made distinctions between “ethics” and “morality”. I used to distinguish “morality”, as reducing ethics to simple compliance with externally given norms, from “ethics”, as concerned with inquiry into what really is right. But as a result of engagement with the literature on Kant, I have adopted a more Kantian usage that makes “morality” too a subject of inquiry in the best Socratic sense. I now use the word “moral” in the broad sense of what used to be called “moral philosophy”.

However sophisticated the underlying judgment may be, any unforgivingly judgmental attitude is prone to find fault with the world and with others. The Moral World-View in Hegel is several steps removed from the traditional attitude that norms are simply given. Its presentation is implicitly a critique of Kantian and Fichtean ethics. Here the judgment is rational. We are seriously thinking for ourselves about what is right. We are sincerely seeking to develop a point of view that is globally consistent and fair, and that takes everything relevant into account. But however nuanced a point of view we develop, it is still ultimately only a single point of view.

Hegel’s approach to ethics is singularly attuned to avoiding self-righteousness in all its forms. Hegelian forgiveness involves the recognition that no single point of view — no matter what subtleties it encompasses — is ever by itself finally adequate in the determination of what is right. For Hegel the ultimate arbiter of what is right is the universal community consisting of all rational beings everywhere, past, present, and future. Because it includes the future, the last word is never said.

This is far removed from the banality that all points of view are equally valid. Rather, everyone gets or should get an equal chance to participate in the dialogue, to be heard and to have their voice considered. But for each of us, the validity of our point of view is subject to evaluation by others, as Brandom has emphasized. We don’t get to individually self-certify. Nor is the validity of a point of view decidable by majority vote. Validation is not a matter of tallying up the conclusions of individuals, or of achieving consensus in a present community. It involves assessment of how the conclusions were reached. Previously accepted conclusions are always implicitly subject to re-examination.

On an individual level too, I like to stress the open-endedness of Aristotelian (and Kantian) practical judgment. The need to act requires that deliberation be cut short at some point. We aim to act with relatively robust confidence that we are doing the right thing, but the best practical confidence is not knowledge. Aristotle takes care to remind us that ethics is not a science. There are many things in life that we do not know, but in which we have justified practical confidence. Ethical judgment is like that.