Sellars on Kantian Imagination

The analytically trained Kantian pragmatist Wilfrid Sellars (1912-1989) is increasing recognized as one of the greatest American philosophers of the 20th century. It has been said that he played a central role in taking analytic philosophy from its empiricist beginnings to a new Kantian stage. He is known for his critique of the “Myth of the Given”, his work on material inference, and his concept of the space of reasons. I found an essay of his on the Kantian productive imagination.

He begins by contrasting two approaches to perceptual judgment. First is a standard empiricist notion that goes as far as possible in reducing judgment to grammatical predication, to the point where the perception itself is treated as a bare this, and all the cognitive work of judgment is concentrated in applying a predicate to the bare this.

“Traditionally a distinction was drawn between the visual object and the perceptual judgment about the object…. This suggested to some philosophers that to see a visual object as a brick with a red and rectangular facing surface consists in seeing the brick and believing it to be a brick with a red and rectangular facing surface: ‘This is a brick which has a red and rectangular facing surface’…. Notice that the subject term of the judgment was exhibited above as a bare demonstrative, a sheer this, and that what the object is seen as was placed in an explicitly predicate position (“The Role of Imagination in Kant’s Theory of Experience”, in In the Space of Reasons: Selected Essays of Wilfrid Sellars, Scharp and Brandom, eds., p. 455).

Rather than pretending that perception gives us only a bare this, we should recognize that at least we talking animals live always already immersed in meaningful content. The most primitive human sense perception involves taking something not just as this, but as something with definite characteristics. This will turn out to be what Kant calls a schema, as distinct from a concept.

“I submit, on the contrary, that correctly represented, a perceptual belief has the quite different form: ‘This brick with a red and rectangular facing surface’. Notice that this is not a sentence but a complex demonstrative phrase. In other words, I suggest that in such a perceptually grounded judgment as ‘This brick with a red and rectangular facing side is too large for the job at hand’ the perceptual belief proper is that tokening of a complex Mentalese demonstrative phrase which is the grammatical subject of the judgment as a whole. This can be rephrased as a distinction between a perceptual taking and what is believed about what is taken…. From this point of view, what the visual object is seen as is a matter of the content of the complex demonstrative Mentalese phrase” (ibid).

In a nonessential decoration of the argument, he mentions “Mentalese”, a term used by analytic philosophers for inner speech. We need not concern ourselves here with whether or not there is a “mental language” distinct from, but patterned on, natural language, as this term suggests. The important point is that in every human perceptual “taking”, there is a kind of linguistic or language-like articulation, which we can express with a phrase consisting of classifying terms and syntactic relations between them.

“We must add another distinction, this time between what we see and what we see of what we see…. How can a volume of white apple flesh [hidden inside the apple] be present as actuality in the visual experience if it is not seen? The answer should be obvious. It is present by virtue of being imagined (p. 457).

“Before following up this point, it should be noticed that the same is true of the red of the other side of the apple. The apple is seen as as having a red opposite side. Furthermore, the phenomenologist adds, the red of the opposite side is not merely believed in; it is bodily present in the experience. Like the white, not being seen, it is present in the experience by being imagined” (ibid).

Here he seems to recall Husserl’s perceptual “adumbrations” or foreshadowings. Sellars is a bit more straightforward and explicit in attributing these to imagination.

“Notice that to say that it is present in the experience by virtue of being imagined is not to say that it is presented as imagined…. Red may present itself as red and white present itself as white; but sensations do not present themselves as sensations, nor images as images. Otherwise philosophy would be far easier than it is” (pp. 457-458).

When we imagine something to be the case, we are most often not aware that we are doing so. We simply think or believe that it is the case. As soon as we already have experience, what Sellars in the thin modern sense calls the “actual” presence of the imagined content comes to us as primitively mixed in with that of the perceived content. It takes work to analytically separate them, and any such separation always has a hypothetical character.

“But while these [hidden] features are not seen, they are not merely believed in. These features are present in the object of perception as actualities. They are present by virtue of being imagined” (p. 458).

As with Husserl’s “presentified” contents, the contributions of imagination are not theoretical constructs, but part of the experience itself.

“We do not see of objects their causal properties, though we see them as having them…. To draw the proper consequences of this we must distinguish between imagining and imaging, just as we distinguish between perceiving and sensing…. Roughly imagining is an intimate blend of imaging and conceptualization, whereas perceiving is an intimate blend of sensing and imaging and conceptualization” (ibid).

I like the way Sellars recognizes the interweaving inherent to these “intimate blends” of imaging and conceptualization.

“Notice that the proper and common sensible features enter in both by virtue of being actual features of the image and by virtue of being items thought of or conceptualized. The applehood [by contrast] enters in only by virtue of being thought of (intentional in-existence)” (pp. 458-459).

“The upshot of the preceding section is that perceptual consciousness involves the constructing of sense-image models of external objects. This construction is the work of the imagination responding to the stimulation of the retina…. The most significant fact is that the construction is a unified process guided by a combination of sensory input on the one hand and background beliefs, memories, and expectations on the other. The complex of abilities included in this process is what Kant called the ‘productive’ as contrasted with the ‘reproductive’ imagination. The former, as we shall see, by virtue of its kinship with both sensibility and understanding unifies into one experiencing the distinctive contributions of these two faculties” (p. 459).

Here we have a very basic Kantian point about the nature of experience — all perception involves imaginative construction. Objects are not just given to us fully constituted.

“Notice once again that although the objects of which we are directly aware in perceptual consciousness are image-models, we are not aware of them as image-models. It is by phenomenological reflection (aided by what Quine calls scientific lore) that we arrive at this theoretical interpretation of perceptual consciousness…. Thus we must distinguish carefully between objects, including oneself, as conceived by the productive imagination, on the one hand and the image-models constructed by the productive imagination, on the other” (pp. 459-460).

In common with Plato, Kant is at pains to point out that everything we experience — including everything we apprehend in inner sense — is appearance. I would say we also have “contact” with reality underlying the appearances, but we do not easily get knowledge of that reality.

“Kant distinguishes between the concept of a dog and the schema of a dog…. [O]ur perceptual experience does not begin with the perception of dogs and houses…. But though the child does not yet have the conceptual framework of dogs, houses, books, etc., he does, according to Kant, have an innate conceptual framework — a proto-theory, so to speak, of spatio-temporal physical objects capable of interacting with each other; objects — and this is the crux of the matter – which are capable of generating visual inputs which vary in systematic ways with their relation to the body of the perceiver ” (p. 460).

Here he explains the important Kantian notion of a schema. Concepts express nonperspectival essences, but schemas are perspectival, involve potentially sensible content, and implicitly include a relation to a perceiver.

“Consider the example of a perceiver who sees a pyramid and is walking around it, looking at it. The concept of a red pyramid standing in various relations to a perceiver entails a family of concepts pertaining to sequences of perspectival image-models of oneself-confronting-a-pyramid. This family can be called the schema of the concept of the pyramid…. Notice that the pyramid-schema doesn’t follow from the concept of a pyramid alone. It follows from the complex concept of pyramid in such-and-such relations to a perceiver” (p. 461).

In a Kantian context, we have no access to a sensible world apart from a perceiver’s perception of it.

“However thin — as in the case of the child — the intuitive representation may be from the standpoint of the empirical concept involved, it nevertheless contains in embryo the concept of a physical object now, over there, interacting with other objects in a system which includes me. It embodies a proto-theory of a world which contains perceivers of objects in that world” (p. 465).

Here we have the basis of Kant’s “transcendental deduction”, which aims to show that perception and imagination effectively already presuppose the same categories that govern understanding. This is how Kant recovers the possibility of objectivity.

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?.)

Husserl on Passive Synthesis

Volume IX of Edmund Husserl’s collected works is entitled in English Analyses Concerning Passive and Active Synthesis. It consists of lectures given between 1920 and 1926, supplemented with various contemporary unpublished notes and manuscripts. Husserl explicitly offers his notion of passive synthesis as a successor to Kant’s idea of a productive synthesis of imagination (see Capacity to JudgeFigurative Synthesis). As usual when I read Husserl, in spite of reservations that some more global concepts he uses seem “too strong”, I am reveling in the richness and originality of his detailed developments.

The term “passive synthesis” has an air of paradox about it, but I have been very interested in the way both Aristotle and Kant deal with aspects of human sentience and sapience that are neither entirely active nor entirely passive, and this is the real significance of this whole topic. In a more general context, Hegel and Paul Ricoeur (who was an acute reader of Husserl) both also have much of value to say about such mixed forms. I tend to think that nothing in the human sphere is ever entirely active or entirely passive.

In spite of Husserl’s pains to distinguish what he called “transcendental” subjectivity (in a sense somewhat different from, but related to, that of Kant) from “psychological” subjectivity — and his early sharp criticism of “psychologism” — translator Anthony Steinbock’s introduction points out that during the less known stage documented in this volume, when Husserl began speaking of a “genetic” phenomenology, he also wrote extensively in the area of philosophical psychology. The material on passive synthesis could be considered a prime instance of this.

For Husserl, all philosophy — and indeed all science, if it is really doing what he thinks it should — ought to make us wiser and better.

He begins with some leading points from what he calls transcendental logic. With extremely broad brush, this is concerned with neither formalization nor real-world inference, but rather focuses on the constitution of meanings.

The main section on passive synthesis begins by noting some aspects of perception that are commonly passed over, including “perspectival adumbration of spatial objects”; “fullness and emptiness in the perceptual process”; how our acquired knowledge can be freely at our disposal; and the relation between being and being perceived.

Next he develops an unusually broad notion of modality, as a kind of modification of the sense of contents. This includes negation, but Husserl is not concerned here with ordinary logical negation. Under negation he discusses things like “disappointment as an occurrence that runs counter to the synthesis of fulfillment”; “partial fulfillment”; and “retroactive crossing out in the retentional sphere and transformation of the previous perceptual sense”. Then he treats doubt, including its origin in conflicting apprehensions and its resolution. Next comes the more standard modality of possibility, which he transforms by dividing it into “open” possibilities and “enticing” possibilities that motivate us. He concludes this subdivision by discussing relations between passive and active modalization, including “position-taking of the ego as the active response to the modal modification of passive doxa [belief]” and “questioning as a multilayered striving toward overcoming modalization through a judicative decision”.

The following subdivision is concerned with the notion of evidence. Here he discusses the “structure of fulfillment” as a “synthesis of empty presentation”; then “passive and active intentions and the forms of their confirmation and verification”, including “picturing, clarifying, and confirmation in the syntheses of bringing to intuition”, “possible types of intuition”, and “possible types of empty presentation”; “intention toward fulfillment [as] the intention toward self-giving”; “epistemic striving and striving toward the effective realization of the presented object”; and “the different relationships of intention and the intended self”. This subdivision concludes with “the problem of definitiveness in experience”, including “the problematic character of a verification that is possible for all intentions and its consequence for belief in experience”; “development of the problem of the in-itself for the immanent sphere”; and “rememberings as the source for an in-itself of objects”.

A long subdivision is devoted to association. Here he will be concerned with motivational relations rather than the psycho-physical causal relations with which “association” is associated in the empiricist tradition. A partial list of the contents includes “presuppositions of associative synthesis”; “syntheses of original time-consciousness”; “syntheses of homogeneity in the unity of a streaming present”‘; “the phenomenon of contrast”; “individuation in succession and coexistence”; “affection as effecting an allure on the ego”; “the gradation of affection in the living present and in the retentional process”; “the function of awakening in the living present”; “retroactive awakening of the empty presentations in the distant sphere”; “the transition of awakened empty presentations in rememberings”; “the difference between continuous and discontinuous awakening”; and “the phenomenon of expectation”.

The final subdivision of the section on passive synthesis is devoted to the stream of consciousness. This includes “illusion in the realm of remembering”; “overlapping, fusion, and conflict of rememberings of different pasts”; “the true being of the system of the immanent past”; “confirmation of self-givenness by expanding into the outer horizon”; “the primordial transcendence of the past of consciousness and the idea of its complete self-giving”; “the problem of a true being for the future of consciousness”; “disappointment as an essential moment of expectation”; and “the constitution of the objective world in its significance for the determinate prefiguring of futural consciousness”.

This is followed by a section on active synthesis, which also treats of “a transcendental, genetic logic”. Voluminous appendices further expand on the topics treated. (See Husserl on Perception; Crossing Out; Enticing Possibilities?; Active and Passive; Husserl on Evidence: Introduction; Intuition, Presentation, Time; Intention and Intuition; Associative Synthesis; Passive Synthesis: Conclusion.)

Constitution of Shared Meaning

The 20th century phenomenological tradition stemming from the work of Edmund Husserl emphasized that all meanings are constituted. With a very broad brush, one might say that Husserl redeveloped many Kant-like insights on a different basis, and with far greater detail in some areas. But like Kant, Husserl focused mainly on how each individual develops understanding for herself. Phenomenologists certainly discussed what they called “intersubjectivity”, but it always seemed to me like an afterthought. Husserl’s own development was quite complex, but it seems to me that the further he went in his later investigations of the constitution of meaning, the more he moved away from his early concern to emphasize that meaning is not something subjective.

It is the original “phenomenology” — that of Hegel — that seems to me to do a much better job of explaining simultaneously how meanings are constituted by us and yet how they are not subjective. Hegel does this by starting from the point of view of the development of shared meaning, and ultimately conceiving the constitution of meaning as a part of a great process extended across time and space. The process is grounded in concrete mutual recognition that nonetheless potentially extends to all rational beings. Individuals play an essential role in this as the anchoring points for its actualization, but do so as participants in free and open dialogue with others, rather than as the “owners” of meanings considered as private. Hegel used the Christian notion of the Holy Spirit manifesting between the members of a community as a philosophical metaphor for this.

Saying as Ethical Doing

Saying is a distinctive kind of doing. This goes way beyond the physical uttering of words, and beyond the immediate social aspects of speech acts. It involves the much broader process of the ongoing constitution of shared meaning in which we talking animals participate.

Before we are empirical beings, we are ethical beings. Meaning is deeply, essentially involved with valuations. The constitution of values is also an ongoing, shared process that in principle involves all rational beings past, present, and future. Our sayings — both extraordinary and everyday — contribute to the ongoing constitution of the space of reasons of which all rational beings are co-stewards. We are constantly implicitly adjudicating what is a good reason for what.

If immediate speech acts have ethical significance, this is all the more true of our implicit contributions to these ongoing, interrelated processes of constitution of meanings, valuations, and reasons. Everything we say becomes a good or bad precedent for the future.

Aristotle consistently treated “said of” relations in a normative rather than a merely empirical, factual, representational or referential way. Brandom has developed a “normative pragmatics” to systematically address related concerns. Numerous analytic philosophers have recognized the key point that to say anything at all is implicitly to commit oneself to it. As Brandom has emphasized, this typically entails other commitments as well. I would add that every commitment has meaning not only in terms of the pragmatic “force” of what is said, but also as a commitment in the ethical sense.

It is through our practices of commitment and follow-through that our ethical character is also constituted. As Robert Pippin has pointed out that Hegel emphasized in a very Aristotelian way, what we really wanted is best understood starting from what we actually did. In contrasting all this with the much narrower concept of speech acts, I want to return to an emphasis on what is said, but at the same time to take the “said” in as expansive a sense as possible. This is deeply interwoven with all our practical doings, and to be considered from the point of view of its actualization into a kind of objectivity as shared meaning that is no longer just “my” intention.

Real-World Reasoning

I think most people most of the time are more influenced by apprehended or assumed meanings than by formal logic. What makes us rational animals is first of all the simple fact that we have commitments articulated in language. The interplay of language and commitment opens us to dialogue and the possibility of mutual recognition, which simultaneously ground both values and objectivity. This opening, I’d like to suggest, is what Hegel called Spirit. (See also Interpretation.)

Formal and Transcendental Logic

One of Edmund Husserl’s works that I had not looked at before is Formal and Transcendental Logic (German ed. 1929). This will be a very shallow first impression.

Although he goes on to argue for the importance of a “transcendental” logic, Husserl is far from denigrating purely formal logic. He explores developments in 19th century mathematics that have some relation to logic, like Riemann’s theory of abstract multiplicities. Formal logic itself comprises both a theory of objects and a theory of forms of judgment; Husserl aims to give a deeper meaning to both. Ultimately, he wants to give a “radical” account of sense, or meaning as distinguished from reference. For Husserl, we get to objects only indirectly, through the long detour of examining sense.

Having previously severely criticized the “psychologistic” account of logic made popular by John Stuart Mill, here he is at some pains to establish the difference between transcendental and psychological views of subjectivity. Husserl often seems overly charitable to Descartes, but here he writes, “At once this Cartesian beginning, with the great but only partial discovery of transcendental subjectivity, is obscured by that most fateful and, up to this day, ineradicable error which has given us the ‘realism’ that finds in the idealisms of a Berkeley and a Hume its equally wrong counterparts. Even for Descartes, an absolute evidence makes sure of the ego (mens sive animus, substantia cogitans [mind or soul, thinking substance]) as a first, indubitably existing, bit of the world…. Even Descartes operates here with a naive apriori heritage…. Thus he misses the proper transcendental sense of the ego he has discovered…. Likewise he misses the properly transcendental sense of the questions that must be asked of experience and of scientific thinking and therefore, with absolute universality, of a logic itself.”

“This unclarity is a heritage latent in the pseudo-clarities that characterize all relapses of epistemology into natural naivete and, accordingly, in the pseudo-clear scientificalness of contemporary realism. It is an epistemology that, in league with a naively isolated logic, serves to prove to the scientist… that therefore he can properly dispense with epistemology, just as he has for centuries been getting along well enough without it anyway.”

“… A realism like that of Descartes, which believes that, in the ego to which transcendental self-examination leads back in the first instance, it has apprehended the real psyche of the human being… misses the actual problem” (pp. 227-228).

“For a radical grounding of logic, is not the whole real world called in question — not to show its actuality, but to bring out its possible and genuine sense and the range of this sense…?” (p. 229).

“The decisive point in this confusion… is the confounding of the ego with the reality of the I as a human psyche” (p. 230).

This last is an argument I have been concerned to make in a Kantian context. However one chooses to pin down the vocabulary (I have been generally using “ego” for the worldly psychological thing, and “I” as actually referring to a nonempirical, transcendental index of certain commitments), the distinction is decisive. Empirical subjectivity in the realm of psychology and transcendental subjectivity in the realm of meaning are extremely different things, even though we live in their interweaving. These days I’m inclined to identify the human expansively with that possible opening onto the transcendental of values — or “Spirit” in a Hegelian sense — rather than contractively with the “merely human” empirical psyche.

Nondualism?

As far as I know, the explicit term “nondualism” was first used in certain strands of Mahayana Buddhism. I believe it later was adopted by the Vedanta school of Hindu scholastic philosophy. I was fascinated with these as a young man, and was for a time much absorbed in developing a sort of Alan Watts style interpretation of Plotinus’ emphasis on the One as a similar kind of radical nondualism.

Radical nondualism goes beyond the rejection of sharply dualist views like those of Descartes on mind and world, and the different religious dualisms like those of Augustine, the Zoroastrians, the Gnostics, the Manichaeans, or the Samkhya school of Hinduism. Each of these latter has important differences from the others, but what unites them is the strong assertion of some fundamental duality at the heart of things. Radical nondualism aims to consistently reject not only these but any vestige of duality in the basic account of things.

The point of view I would take now is that many useful or arguably necessary distinctions are often formulated in naive, overly blunt ways. We should strive to overcome our naivete and our excessive bluntness, but that does not in any way mean we should try to overcome distinction per se. There can be no meaning — even of the most spiritual sort — without some sort of distinction between things. “All is One” is at best only a half-truth, even if it is a profoundly spiritual one.

Pure Difference?

A common theme here is the conceptual priority of difference over identity. I think that identity is a derived concept, and not a primitive one (see also Aristotelian Identity).

The French philosopher Gilles Deleuze (1925-1995) in Difference and Repetition and other works argued that a pure notion of difference is by itself sufficient for a general account of things. In information theory, information is explained as expressing difference. In Saussurean structural linguistics, we are said to recognize spoken words by recognizing elementary differences between sounds. In both cases, the idea is that we get to meaning by distinguishing and relating.

Deleuze initially cites both of these notions of difference, but goes on to develop arguments grounded largely in Nietzsche and Kierkegaard, whom he uses to argue against Plato and Hegel. His very interesting early work Nietzsche and Philosophy was marred by a rather extreme polemic against Hegel, and in Difference and Repetition he announces a program of “anti-Platonism” that reproduces Nietzsche’s intemperate hostility to Plato. Nietzsche blamed Plato for what I regard as later developments. Neither Plato nor Aristotle made the kind of overly strong assertions about identity that became common later on.

In The Sophist and elsewhere, Plato had his characters speak of Same, Other, and the mixing of the two as equally primordial. Hegel took great pains to elaborate the notion of a “difference that makes a difference”. But Deleuze wants to argue that Plato and Hegel both illegitimately subordinate difference to identity. His alternative is to argue that what is truly fundamental is a primitive notion of difference that does not necessarily “make a difference”, and that come before any “making a difference”. (I prefer the thesis of Leibniz that indiscernibility of any difference is just what identity consists in.)

This is related to Deleuze’s very questionable use of Duns Scotus’ notion of the univocity of being, both in general and more particularly in his interpretation of Spinoza. For Deleuze, pure difference interprets Scotist univocal being.

I frankly have no idea what led to Deleuze’s valorization of Scotus. Deleuze is quite extreme in his opposition to any kind of representationalism, while Scotus made representability the defining criterion of his newly invented univocal being. It is hard to imagine views that are further apart. I can only speculate that Deleuze too hastily picked out Scotus because he wanted to provocatively oppose the 20th century neo-Thomism that had considerable prominence in France, and Scotus is a leading medieval figure standing outside the Thomist tradition.

For Deleuze, univocal being is pure difference without any identity. Difference that doesn’t make a difference seems to take over the functional role that identity has in theories that treat it as something underlying that exceeds any discernibility based on criteria. I don’t see why we need either of these.

I think Deleuze’s bête noir Hegel actually did a better job of articulating the priority of difference over identity. Hegel did this not by appealing to a putative monism of difference and nothing else, but by developing correlative notions of “difference that makes a difference”, and a kind of logical consequence or entailment that we attribute to real things as we interpret them, independent of and prior to any elaboration of logic in a formal sense.

In Hegel’s analysis as explicated by Brandom, any difference that makes a difference expresses a kind of “material” incompatibility of meaning that rules out some possible assertions. This is just what “making a difference” means. Meanwhile, all positive assertions can be more specifically analyzed as assertions of some consequence or entailment or other at the level of meaning (see Material Consequence). Every predication is analyzable as an assertion of consequence or entailment between subject and predicate, as Leibniz might remind us. It is always valid to interpret, e.g., “a cat is a mammal” as an inference rule for generating conclusions like if Garfield is a cat, then Garfield is a mammal.

What is missing from Deleuze’s account is anything like entailment, the idea of something following from something else. This notion of “following”, I am convinced, is prior to any notion of identity applicable to real things. Without presupposing any pre-existing identities of things, we can build up an account of the world based on the combination of differences that make a difference, on the one hand, and real-world entailments, on the other. Identity is then a result rather than an assumption. Meanings (and anything like identity) emerge from the interplay of practical real-world entailments and distinctions. It is their interplay that gives them definition in terms of one another.

Deleuze was a sort of ontological anarchist, who wanted being to be free of any pre-existing principles. While I agree that we can’t legitimately just assume such principles, I think this is very far from meaning that principles are irrelevant, or actually harmful. On the contrary, as Kant might remind us, principles are all-important. They aren’t just “given”. We have to do actual work to develop them. But if we have no principles — if nothing truly follows from anything else, or is ruled out by anything else — then we cannot meaningfully say anything at all.

Mechanical Metaphors

Perhaps the greatest contribution of the Italian physicist, astronomer, and engineer Galileo Galilei (1564-1642) — regarded by many as the single most important originator of modern, mathematically oriented natural science — was a unified explanation of both astronomical and earthly phenomena by the same set of mathematical principles for analysis of the behavior of physical bodies and matter. This was a generalized mechanics of solid bodies.

The tremendous power of this new way of understanding the physical behavior of bodies is undeniable. At least until the computer age, it has been the main basis of modern engineering and technology.

A historical side effect of this immensely successful development has been the promotion of solid-body mechanics as a kind of privileged metaphor for causality in general. I’ve several times discussed the transformation of Aristotle’s notion of efficient cause (most fundamentally, the means to actualization of an end) into the very different notion of “driving” cause or “motor” by medieval and early modern authors (see Efficient Cause, Again; Suárez on Agents and Action; Effective vs “Driving”; Not Power and Action). In combination with a very un-Aristotelian tendency to reduce other causes to efficient causes, this created a ripe condition for the spread of a view of causality in general in terms of metaphors based on solid-body mechanics. We are now so used to this that it takes effort to imagine any other view.

But the solid-body interaction metaphor ultimately leads to an impoverished, overly narrow view of causality in general. (For an alternative, see Aristotelian Causes.) Even within mechanics proper, solid bodies are no longer the paradigmatic, privileged case. At scales that are too small or too large, analogies to the behavior of medium-sized solid bodies break down. In broader contexts, wave phenomena are as important as the analysis of solid bodies. The great Roman poet-physicist Lucretius already had the insight that in the general case, atoms in aggregate behave more like liquids than like solids.

Irreducible to any purely mechanical paradigm, disciplines like earth sciences, ecology, medicine, economics, and computer science provide many examples of more complex and subtle interactions and structures that suggest a new need for something more like an Aristotelian view of causality, as having more to do with forms of things than with force.