Perceptual Intuition

Perceptual Intuition

Perception and intuition are usually opposed to each other: what is perceived is not intuited and what is intuited is not perceived. The senses perceive and reason (intellect) intuits. We know material objects by perception and abstract objects by intuition. Empiricism declares perception to be the basis of knowledge (and the criterion of existence); rationalism declares reason to be the basis of knowledge (and the measure of reality). Intuition and rationalism go together; perception and empiricism go together. There is a grand dichotomy: intuition doesn’t encroach on perception’s territory, and perception doesn’t encroach on intuition’s territory. It is true that Kant spoke of sensory “intuitions”, but he is an exception—and anyway he didn’t mean to claim that perception is a species of rational intuition in the style of classical rationalists (what he did mean is open to interpretation). The pivotal point is that perception and intuition have been taken as separate and distinct—indeed, as mutually exclusive. I will argue that this is wrong, deeply so.

The operative considerations are not unfamiliar, but their significance has not been fully appreciated. A seen object presents a surface to the eye; it doesn’t present all its surfaces (or its interior). It has a front and a back. The back is not visible. The viewer has no sense-datum of the back side of the object. Yet the hidden side doesn’t go unrecognized; it isn’t omitted from the viewer’s total perceptual experience. He knows it is there, as much as the facing side. We might say that he has a sense of it but not an impression. A being with eyes on stalks that can view the object from all angles would have an impression of all aspects of the object; there would be no need to fill in the gap with…what? What word should we use? Should we say postulation, or imagination, or hypothesis, or inductive reasoning? These all sound too intellectualist, too deliberate, though not without a certain suggestiveness—an extra mental act has to be performed beyond mere retinal responsiveness (the proximal stimulus). The given must be supplemented somehow. I think the best word is intuition, defined as follows: “the ability to understand something immediately, without the need for conscious reasoning”; “instinctive” (OED). We can paraphrase this as, “the ability to know something instinctively without explicit rational thought”. The emphasis is on the pre-rational, automatic, pre-conscious, implicit, unreflective, non-conceptual, taken-for-granted, primitive. Little children can do it, also animals. It is probably largely innate. Clearly, it is vital to survival (you have to know that things have unseen sides). We can add it to Russell’s “knowledge by acquaintance” and “knowledge by description”—this is “knowledge by intuition”. We are not acquainted with the back sides of objects, but neither do we infer them by discursive methods (“the hidden side of the object whose front side I am now acquainted with”). Intuitive knowledge is something different from acquaintance knowledge and descriptive knowledge, as conceived by Russell. It is a step up from mere acquaintance and a step down from conceptualized description. Thus, we can say that ordinary perceptual experience involves intuition as well as sensation. In fact, it would be possible for intuition to exist in the absence of sensation, as in a case of blindsight: someone might intuit an object by means of the eyes and be incapable of receiving visual sensations—seeing would be nothing but intuiting. As things stand, however, seeing is an amalgam of the two—part sense-datum and part intuitive apprehension. It has a kind of dual intentionality. Intuition is integral to perception, pace the empiricists. We might say that they were guilty of an aspect-object confusion: they thought the perceived object was nothing but the aspect presented, forgetting that objects are seen as having hidden aspects too. The perceptual is infused with the intuitive, and to that degree overlaps with other sorts of intuitive apprehension, as with apprehension of numbers. A being with all-inclusive vision (eyes on stalks) might view normal human and animal vision as decidedly in the intuitive category along with other varieties of intuition, and to that degree epistemically suspicious. What is this “intuition” that outstrips good old-fashioned seeing—the kind where you have sensations of the whole object. Now that is the type of seeing you could rest a whole epistemology on! That would be true empiricism, not this semi-intuitive nonsense—what even is intuition? For these beings, there is only pure sensation (acquaintance) and conscious reasoning therefrom, not a peculiar kind of intuition that steps in to take up the perceptual slack. These beings are hyper-empiricists, the genuine article.

How about mathematical intuition? This is a large subject, but let me focus on thinking of the number 2. We don’t normally think of this as a type of sense perception; we think of it as pure intuition—“mathematical intuition”. It could be performed in the complete absence of any sensory materials. But in the human case this is clearly not so: such intuition comes surrounded by sense perception. I think of the number 2 when I see or hear the numeral “2”, or when I see two chickens cross the road. Could I think of that number in the absence of any such experience? It’s hard to say, given that we are deeply sensory beings—though not exclusively so. As a matter of psychological fact, we think of numbers with the aid of sensory material—as we perceive objects with the aid of intuition. Numbers present themselves to our mind under a dual guise—abstractly and concretely, rationally and perceptually. In particular, numerical symbols play a vital role in mathematical thought, which is why advances in mathematical notation were advances in mathematics itself. There is a reason why mathematical formalism is an attractive doctrine and Platonism feels like a stretch—it is easy to commit a sign-object error in mathematics. It is as if numbers come disguised as numerals and we have to see through the disguise. Thus, mathematical intuition is drenched in sense perception; it is partly “empirical”. The end is abstract but the means is (partly) concrete. We don’t apprehend numbers in the complete absence of sensory experience. Pure rationalism is not psychologically realistic. Thus, in the human case intuition needs perception, as perception needs intuition. This may not be the ideal situation, epistemologically, but it is the actual situation.

Accordingly, classical empiricism is not true and classical rationalism is not true. We need a mixed epistemology. What should we call it? Rational empiricism? Empirical rationalism? The trouble is both terms are tainted with the same mistake, i.e., exclusiveness. The point of the view I am suggesting is that traditional epistemology is too dichotomous, so we need a more inclusive unitary label. We could try “intuitionism” but that already has an established use and fails to capture the sensory element. I have toyed with “quasi-intuitionism” and “experiential intuitionism”, but for various reasons don’t like them much. The best I have able to come up with is “general intuitionism”: it captures the idea of extending intuition into the theory of perception, thus unifying epistemology; and it echoes Einstein’s “General Theory of Relativity”, with its attempt to integrate apparently different domains. The thought is that intuition (in the sense defined) is more ubiquitous than has been supposed, more fundamental; it’s everywhere. Perception is not an intuition-free zone, capable of standing apart from other areas in which intuition has been taken seriously (mathematics, ethics, logical analysis). We don’t need to preach the prevalence of perception in the theory of knowledge; it has had enough propaganda on its behalf already. So, “general intuitionism” it is. The idea is not to claim that the concept of intuition will reduce the field of knowledge to something more natural or better understood; there is plenty about intuition that is obscure and ill-understood. But it is real and theoretically indispensable. It is a biological fact about the human (and animal) mind, akin to creativity and problem-solving. It is obscurely linked to imagination. In epistemology, it serves to overcome a simplistic dichotomy that has plagued the subject—the dichotomy between sense perception, on the one hand, and rational thinking, on the other. These are not as disjoint as has been supposed, though they are clearly different in many ways.[1]

[1] Intuition was not a concept in good standing with classical empiricists and rationalists, because neither theory can find room for it within their official platforms. Empiricism finds it an embarrassment on account of its non-sensory character—it seems like an upsurge of rationalism at the heart of perception. Rationalism doesn’t care for its instinctual animal character, its bypassing of conscious calculated reason—an upsurge of the primitive in the rational soul. Intuition makes man an intuiting being as well as a thinking being—a sort of spontaneous leaper in the dark. How can it be rationally defended? Knowing things intuitively seems to the rationalist like not knowing them at all—a kind of guessing. The empiricist, for his part, balks at the foundation of knowledge presupposing resources not derivable from brute sensation. Thus, empiricism and rationalism are constitutionally anti-intuitionist. Intuition represents an epistemological viewpoint alien to them both. To me it seems like a rich field for future investigation, not something to either contemptuously discard or flakily celebrate. I look forward to the Journal of Intuition Studies.