Berkeley on Perception

George Berkeley (1685-1753) is most famous for his provocative claim that material objects don’t really exist. Positively, he claimed that “to be is to be perceived”. Berkeley took as a starting point the view of Descartes and Locke that perceptions are “ideas” in the mind, but took issue with the further assumption of Descartes and Locke that ideas nonetheless also “represent” things that exist independent of the mind. It seems to me that the implicit concept of mind in this kind of usage assumes way too much, but for now I won’t dwell on that.

Berkeley has been the subject of superficial ridicule as a poster child for extreme subjectivism, but that is a caricature. Famously, he is supposed to have maintained, e.g., that a tree falling in the woods and heard by no one makes no sound. As 20th century analytic philosophers have noted, however, even if his positions are ultimately untenable, the quality of his arguments is actually quite high. Apart from the abstract “metaphysical” question of the actual existence of external objects, he also generally wanted to vindicate common sense.

Far from denying the existence of any objective reality, what he really wanted to do was articulate an alternate account of objectivity, based on something other than the independent existence of discrete objects. He had two different kinds of responses on the falling tree. One invokes counterfactual conditions; all that is of practical relevance to us are the conditions under which a perception would occur. The other invokes God as a universal witness.

From within the tradition of British empiricism, Berkeley partially anticipates the non-representationalist accounts of objectivity developed by Kant and Hegel, using the resources of a kind of Christian Platonism. Unlike Kant and Hegel, he flatly asserts that what really exists are what he calls spirits, which combine Christian-Platonic attributes with those of minds in a broadly Cartesian-Lockean sense.

A bit like the monads of Leibniz but without the infinite nesting and mutual inclusion Leibniz posited, Berkeley’s spirits are inherently active, and inherently endowed with perception. Spirits have experience that is expressed in purely immanent and immediate — but entirely passive and inert — contentful ideas.

Berkeley wrote an important early work on the theory of vision, arguing that what we really see is immediate phenomena of light and color, rather than inferred “things”. This was an important source for phenomenalism in early 20th century philosophy of science. Like the later phenomenalists, he tried to explain all cognitive error as bad inference from good immediate perception. From this point of view, “ideas” cannot be wrong, because they are purely immediate and purely inert; the possibility of error depends on the actions of finite spirits.

The common tradition of Cartesianism and British empiricism insists that there is a layer of immediate apprehension that is immune to error, and wants to ground knowledge and science by more authentically getting back to that immediate layer. I think Kant and Hegel convincingly showed that everything we experience as immediate actually has a prehistory, so that immediacy itself is only an appearance, and all immediacy that we experience is really what Hegel called mediated immediacy. Mediated immediacy has the same general kind of explanation as what is called “habit” in translations of Aristotle. We “just know” how to ride a bicycle once we have already learned. We don’t have to think about it; we just spontaneously do it. Similarly, I think “immediate” perception involves a complex unconscious application of categories that is affected by large bodies of previous experience.

Thus I want to say that there is no layer of human experience that is immune to error. On the other hand, through reflection and well-rounded judgment, we genuinely but fallibly participate in objectivity. Objectivity is not something that is simply “out there”; it is a real but always finite and relative achievement.

Descartes Revisited

Descartes is among my least favorite of those conventionally termed great philosophers. My treatment to date has been mainly limited to a few dismissive remarks. Here I’d like to add a few “historiographical” points of demarcation.

Insofar as there is general consensus among scholars, Descartes (1598-1650) first and foremost has claim to fame as a very influential promoter of something recognizably close to modern scientific method. He is often credited with the invention of analytic geometry, based on an early recognition of the systematic isomorphism between geometry and algebra. Galileo (1564-1642) had already taken up an approach to natural science based on mathematical analysis, which Descartes enthusiastically adopted. Descartes particularly promoted a methodology based on clear and distinct ideas, which he held to give certain knowledge. He advocated an orderly progression from the simple to the complex.

On a broad social level, Descartes is remembered for promoting the independence of scientific investigation, particularly from the doctrinal concerns of the Catholic Church. But he was also a religious thinker. While confessing in a private letter that he did not literally believe various details of received scripture, he was very engaged with proofs of the existence of God.

Numerous scholars have pointed out that outside the domains of mathematics and natural science, Descartes in many ways remained close to the Latin scholasticism of which he has been commonly regarded as the slayer. In Descartes and the Modern Mind (1952), for example, Albert Balz argued at length that the thought of Thomas Aquinas was an essential precursor to Descartes. I note that Augustine had already emphasized the importance of the interpretive role of reason, even in matters of faith. On Aquinas’ account, God gives us not only revelation, but also the natural light of reason. In Summa Contra Gentiles, Aquinas addressed questions of philosophy and theology entirely from the point of view of that “natural light”, while aiming to show that the natural light of reason independently leads to many of same truths he attributed to revelation. Descartes makes great use of a similar concept of the natural light of reason.

Both Descartes and Aquinas thought the natural light of reason, properly understood, gives us truths, full stop. I think it gives us invaluable criteria for judgment and interpretation, while always in principle leaving room for discussion about what conclusions should be drawn. I also think the “natural light” itself comes to us in degrees, and is never a simple or unproblematic possession.

A different strand of Latin scholastic thought tended to claim that all human knowledge originates in sensible images, while attributing such a view to Aristotle. (I think this is overly strong, and that Aristotle only meant to defend the pragmatic value of sensation against Platonic skepticism about all deliverances of sense.) Descartes famously argued that sensible images are not the only source of knowledge, and I think that is true, as far as it goes.

Here is where Descartes’ theses about clear and distinct ideas come into play. A methodological discipline based on examining whether our ideas are clear and distinct is an important source of human knowledge. Again, this much I can agree with, but I think clarity and distinctness are relative criteria and not absolutes. As relative criteria, they have been implicitly employed by most if not all serious thinkers. I take such evaluations to have been a major implicit concern of Platonic and Aristotelian dialectic, which in part aims to discern meanings that are more clear and distinct.

Descartes effectively claimed that clarity and distinctness are absolute, decidable properties of ideas. One of the broadly scholastic views he sharply criticized was that our best knowledge of sensible things is only “probable”. Descartes claimed that the results of his methodological analyses were certain, in the same way that mathematical conclusions follow with certainty from their premises. This goes well beyond the claim that there is practical value in such methodology.

Building on arguments of Augustine and Avicenna, he also famously gave great importance to the claim that immediate contents of the mind give evidence of unconditional certainty of the abstract existence of something. The very possibility that I could be deceived implies the abstract existence of an abstract something that could be deceived. Further, if something in any way appears to me to be such and such — even if I am wrong about all the details — independent of all the details, the barest fact of the appearance implies that some appearance generically “exists”.

The “I” that is in this way proven to exist and the appearance that is proven to exist are both extreme abstractions. Even Descartes did not claim that either of these existences by itself gives us any further knowledge. From this basis alone, I could still be entirely mistaken about the kind of being that I am, and about every detail of what appears to me to be the case. In spite of the famous Cartesian doubt, Descartes actually wanted to makes strong claims of certainty and to refute skepticism. Many readers have concluded, though, that he opened the door for a new, more global form of skepticism, because what he clearly establishes as certain seems so utterly lacking in content.

I would hasten to add that unreasonable, excessive skepticism about human knowledge is best refuted by successful achievements of goals in real-life situations. Only a hypocrite could claim to live in the world with no well-founded beliefs whatsoever. The ancient Skeptics were only “skeptical” about theoretical accounts of things, not about practical concerns of everyday life.

By setting the bar too high and aiming at absolute certainty, Descartes actually opened the door for more radically subjectivist views that no one in the ancient world would have taken seriously (and not just because ancient people were naive). At the same time, he was very impatient with “dialectic”, and tended to foreshorten discussions of meaning and interpretation, in favor of claims that certain contents are unequivocally clear and distinct. Thus the ultimate result of his thought oscillates unstably between extremes of “Cartesian” skepticism and dogmatism.

Another point on which Descartes has been very influential is his strong representationalism. For Descartes, strictly speaking we never have practical knowledge of things in the world, only knowledge about contents of our mental representations, insofar as they are clear and distinct. In particular, we only know bodies through our mental representations of them. Rather than consisting in an interpretive stance of a situated being in the world, the Cartesian cogito achieves its purely subjective certainty in a way that is supposed to be peculiarly “outside” the real world altogether.

Unlike the representationalism of Locke, which is grounded in a kind of empirical psychology, that of Descartes is closely bound up with an ontological mind/world dualism more radical than anything Plotinus, Augustine, or Avicenna ever contemplated. For Plotinus, Augustine, and Avicenna, the soul was a very special kind of “something” existing in the real world, even if for Plotinus and Augustine it was not a “subject” in the sense of something underlying something else. For Locke — the other great early modern promoter of representationalism — our mental worlds are ultimately contained within the natural world. For Descartes, there is the world and there is the soul, and never the twain shall meet. The soul has its own mental world where it seems to relate directly only to God, and human knowledge occurs only in that mental world.

It is due to this unprecedentedly radical mind/world dualism of Descartes, I think, that virtually no one — even among his admirers — wants to uphold his metaphysics. This is an extreme example of what Hegel called “alienation”.

Historiography, Inferentialism

Having laid out some preliminaries, I’ve begun to circle back to more questions of historical detail related to the development here, and it seems fitting to summarize the motivations driving these more historical notes. History is all about the details, but in any inquiry, what are actually higher-order questions about methodology ought to inform primary investigations. We never just have data; it always has to be interpreted, and this involves questions about methodology. With history, this often involves critical examination of the applicability of categories that may tend to be taken for granted. Thus, I am adding notes about the application of various categories or concepts in particular historical settings, and about historical details that seem to have larger methodological significance.

I’m looking back at the history of philosophy (and, to some extent, broader cultural developments) from a point of view inspired by the “inferentialism” of Brandom (taking this as a general name for his point of view), as well as by my own ideas for a revitalized Aristotelianism. In Tales of the Mighty Dead and elsewhere, Brandom himself has effectively placed the historical roots of his development in the broad tradition of early modern philosophical rationalism, including the work of Descartes, Spinoza, and Leibniz. I find standard connotations of the term “rationalism” rather problematic, and want to separate Descartes — of whom I am much more sharply critical than Brandom seems to be — from Spinoza and Leibniz, for whom I find additional reasons to be sympathetic. Brandom has contributed to a new understanding of Kant, and has developed a landmark reading of Hegel. I want to help support the broad thrust of these with historical considerations, while reconnecting them with fresh readings of Aristotle, Plato, and other historical philosophers. With some caveats and in spite of Brandom’s own brief comments, I also want to suggest a possible rapprochement with key insights of 20th century French “structuralism”.

A key point common to most of the tendencies mentioned above is an emphasis on the role of difference in making things intelligible. In the context of philosophical arguments, this means that critical distinctions are as important as positive assertions. Contrasts not only greatly facilitate but largely shape understanding. Brandom himself has developed the contrast between inferentialism and the representationalism of Descartes and Locke. He has made large use of Wilfrid Sellars’ critique of a “Myth of the Given” associated with most varieties of empiricism, and has also referenced the critique of psychologism developed by Frege and others in a logical context.

I have been using the term “mentalism” for a privileging of contents that are supposed to be immediately present to a personal “mind” that is itself conceived mainly in terms of immediate awareness. It seems to me that Descartes and Locke’s version of this was a historically specific combination of all the above notions from which an inferentialism would seek to distinguish itself — representationalism, the Myth of the Given, and psychologism. I have been concerned to point out not only that Cartesian-Lockean mentalism has historically specific antecedents that long predate modernity (going back to Augustine, with some foreshadowing in Plotinus), but also that a proto-inferentialist countertrend is actually even older, going back to Plato and Aristotle’s emphasis on the primacy of reason and reasoned development.

In A Spirit of Trust, Brandom has among many other things expanded on Hegel’s critique of Mastery. I find this to be of tremendous importance for ethics, and consonant with my structuralist sympathies. I have been concerned to point out how extreme claims of mastery are implicit in the various historical kinds of voluntarism, which all want to put some notion of arbitrary will — or authority attributed one-sidedly to such a will — ahead of consideration of what is reasonable and good.

Usual generalization caveats apply to statements about “isms”. In any particular case where the terms seem to apply, we need to look at relevant details, and be alert to the possibility that all aspects of a generalized argument may not apply straightforwardly. (See also Historiography; History of Philosophy.)