Common Sense and Philosophy

Philosophers often assume that there is something called common sense, or commonsense belief, with which their theories may agree or disagree. This gives rise to the idea that there is such a thing as commonsense philosophy, or anti-commonsense philosophy. I think this is a mistake for a number of reasons. The first reason is that the phrase “common sense” doesn’t mean what it is taken to mean: it doesn’t describe a category of beliefs but a way of approaching problems.[1] The OED gives us “good sense and sound judgment in practical matters”. To have common sense is to have the ability to solve practical problems in a sensible manner, i.e., not to do things in a silly or inefficient way. It is not common sense to believe that the earth goes round the sun, or that we see material objects, or that we know we have two hands. It is common sense to wash a car with soapy water not beer, or to look before you leap. The phrase “common sense” is not synonymous with “common beliefs”: the latter phrase means something like “widely held beliefs”. Nor does it mean “beliefs people hold without knowing any science or philosophy”. The phrase “common sense beliefs” is nonsensical: there are common sense methods but not commonsense beliefs. You can have beliefs that don’t require any specialized knowledge, but these are not instances of common sense: you are not exercising your common sense if you believe that the sun rises in the morning or that there are a great many material things in the world. So, the phrase “common sense (beliefs)” does not identify any class of beliefs that might conflict with philosophical theories or theses. It is a misnomer, a kind of category mistake. Its cash-value appears to be something like “beliefs that don’t derive from science or philosophy”, though even that formulation is riddled with difficulty (how about the belief that the post office is closed on Sunday?). So far, then, we have not identified a class of beliefs that are philosophically significant and in conflict or agreement with philosophical theories, but not the province of philosophy as an academic discipline. We have no general characterization of such a class of beliefs. Having good practical judgment is not the same as having a specific set of beliefs with which a philosopher might agree or disagree.

Part of the idea behind the offending phrase is that of beliefs that everyone shares. Some beliefs are held by a select few, often specially trained, but some are held by everyone just in virtue of being human. So, at any rate, it is supposed. We thus have the idea of universal beliefs—what the human species believes as a matter of course. We can then oppose these species-wide beliefs to the beliefs of specially trained philosophers (or scientists). Just as there are linguistic universals and conceptual universals and perceptual universals, so there are doxastic universals—things we all believe just by being human. Indeed, these beliefs may be shared by creatures other than the human kind, just in virtue of their being believers in anything (animals, aliens, non-conformists of various stripes). Let us then substitute the phrase “universal beliefs” for “commonsense beliefs” so that we can say that there are universal beliefs with which the philosopher might agree or disagree. For example, it might be said that we all believe that we see material objects and that philosophers of perception might agree or disagree with that proposition. The trouble with this formulation is that it is false: there are no such universal beliefs. Not everyone believes that we see material objects—some may be agnostic or skeptical or in open dissent or just uncomprehending. The thing about beliefs is that they are friable, labile, and mercurial: they vary tremendously between people and over time, and without much effort. People naturally disagree; and their beliefs can change at the drop of a hat. We don’t have fixed beliefs as we have fixed eye color: that is why it is not difficult to persuade people that we do not see material objects (but only sense-data). We can’t easily change how we see or smell things, but we can effortlessly change what we believe. Universality is not the natural condition of belief; diversity is. That is the joy of belief, but also its curse: you can believe virtually anything, which sets you free, but it also sets you up for error and credulity. Some people are constitutionally contrary, making a point of believing what others don’t believe. Beliefs are plastic and malleable; hence they are not naturally or nomologically universal. And the more contestable they are the more disagreement there will be; thus, the closer to philosophical disputes the less universal. Take free will: the belief in free will is not humanly universal, precisely because it is open to philosophical dispute. I do not think it is possible to find a single belief that even approximates to universality that is of philosophical relevance. Maybe everyone believes that the earth beneath their feet is solid not gaseous, but that is not a belief with which a philosopher might disagree. Similarly for the belief that one is human or has a body or goes to sleep regularly: some eccentrics might not believe even these things (the nature of belief will not prevent them), but their widespread acceptance is of no relevance to philosophy, since no philosopher disputes them. There is no philosophical school whose main contention is that people are not human or have no body or never sleep.

So, is there nothing to the alleged clash between what people ordinarily believe and what philosophers have contended? Not quite, because some of our beliefs seem to clash with certain philosophical doctrines. I have already mentioned one such case, which is the standard example of the alleged collision between “common sense” and philosophy, viz. the question of whether we (really) see material objects. Is it true that some ordinary people (though not all) believe that we see material objects, while philosophers have denied that? Of course, no one with any knowledge of visual perception thinks that we always see material objects, since we can suffer visual illusions and hallucinations; the question is whether we ever see material objects. It is thought that a great many people believe that we do sometimes see material objects, while some philosophers of perception have denied this. Isn’t that an example of disagreement between ordinary people and (some) trained philosophers? Aren’t many people naïve realists and hence in disagreement with what certain philosophers have maintained? Here is where things get interesting: for it is really not clear that there is any genuine disagreement between the parties involved. Does your average perceiver, who has had no exposure to philosophy, believe that he sees material objects and not surfaces of objects or sense-data of them? Highly doubtful. It would be different if he went around saying as much in so many words, but he doesn’t. Isn’t it just not plausible that he has any such convoluted technical-sounding belief? So, what does he believe about perception? He says things like “I saw the cat a couple of hours ago” in reply to the question “Have you seen the cat recently?” Normally he doesn’t make perceptual statements at all, and if he does it is in a very non-analytical way. If you ask him about sense-data, he will look at you blankly—he has no views about such things. He doesn’t even use general phrases like “material object”—he just says he saw the cat or a car in the driveway. If you press him about sense-data, he might reply “I’ve never thought about it, but now that you bring it up, I do rather think that I see those things more directly than cats and cars”. He isn’t rejecting such notions in his ordinary statements (and corresponding beliefs), so he isn’t committing himself to the doctrine of naïve realism. Nor is his casual talk of seeing cats and cars to be understood as evincing the belief that he sees such things “directly”; he might well allow that he sees them only “indirectly”—yet he still can be said to see them. This is obviously true for surfaces: he might quickly allow that what he really sees directly are surfaces of objects, but point out that this is consistent with seeing whole objects via seeing their surfaces. Do children who employ the verb “see” in conjunction with terms for cats and cars really believe that they see material objects and not surfaces or sense-data? Hardly. The truth is that the philosophical theory of sense-data is not in contradiction to what the ordinary perceiver thinks about perception, if he thinks anything; it is only in contradiction to the philosophical theory of naïve realism, which is a product of the philosophical mind not the mind of the ordinary man, woman, or child. Perhaps such a theory could emerge in the mind of the ordinary person without any formal instruction in philosophy, but it is still a philosophical theory, not a piece of ordinary thought (“common sense”). We may thus venture a generalization: philosophical theories conflict only with other philosophical theories not with what we might call ordinary thinking. Naïve realism is therefore not part of pre-theoretical thought; nor is ordinary thought inconsistent with what philosophers have claimed about perception (they might well concede that in a loose sense we do see cats and cars—they are not invisible like atoms or remote galaxies). This means that there is no such thing as “common sense philosophy” that can agree or conflict with professional philosophy. Ordinary thought and philosophical thought proceed at different levels, the latter being at a meta level with respect to the former. Your ordinary man on the Clapham omnibus is not a closet philosopher, equipped with beliefs that are in contradiction with philosophical theories, whether good or bad. There is really no such thing as ordinary bloke philosophical belief.

Are there any areas in which we can detect a genuine conflict between philosophy and what many people ordinarily believe or assume? I will briefly mention three possible areas intended to illustrate sharp disagreements between philosophical theories and ordinary beliefs. The first is free will: don’t people generally believe in free will, and yet some philosophers have denied its existence? Those philosophers think that determinism rules out free will but many people seem to believe in free will. The obvious reply is that the people who believe in free will define it as freedom from external constraint, in which case it is not in conflict with determinism. Thus, there is no contradiction between what they believe and what incompatibilist philosophers maintain. Those who define free will as requiring indeterminism don’t tend to believe in it (a minority). So, it’s not clear there is anyone left who disagrees with the philosophers. Probably many ordinary people have an inchoate philosophical theory of what free will involves, so they are not counterexamples to the claim that all supposed disagreements with ordinary belief are really disagreements between philosophical theories. The second example is knowledge: don’t the common folk think we have knowledge in cases in which philosophical skeptics think we don’t? Isn’t there a clear conflict here? But again, there are nuances to be noted and distinctions to be drawn: the ordinary chap may well be only too ready to agree that many of our claims to knowledge fall short of absolute certainty, and hence are not strictly knowledge, but insist nevertheless that in a loose sense uncertain propositions can be said to be known—and doesn’t the skeptic agree with this? Not all beliefs are equally unjustified, so we use the word “know” to distinguish the better ones; this is pragmatically sensible. The alleged disagreement is therefore not as sharp as one might initially suppose. The ordinary person doesn’t hold that there are no differences in degree of justification, and he accepts that very few propositions admit of conclusive justification; how we decide to use the word “know”, however, is a matter of pragmatics. We ordinarily describe a room as empty when there is no chunky stuff in it, but it is not as if we deny that it has air or dust in it. It is not clear that ordinary people explicitly or implicitly reject the basic epistemology of the skeptic, though they speak loosely and pragmatically of knowing things. Generally, they have no philosophical opinions at all, so none that are contradicted by other philosophical opinions. They may come to have such opinions as a result of philosophical reflection, but they don’t harbor them in their bosom all along (do young children believe an epistemology that conflicts with that of the skeptic?). Third, and least easily disposed of, we have Zeno’s paradox: surely, it will be said, the folk walking down the street believe that things move! Isn’t it a “commonsense” belief that objects travel from A to B, and isn’t this denied by Zeno? But again, we have to ask what exactly the folk believe (including what children and animals believe regarding motion). Do people believe that objects traverse space in such a way as to occupy successive intermediate places in a continuous manner? That sounds pretty fancy, more like a theory. It is true that people and animals believe they are at different places over time, but that isn’t in conflict with Zeno; he just denies there was continuous spatial transposition over time. To what extent is our understanding of motion conditioned by a theory of how things get to be in different places? Is Zeno really denying what people actually hold as a matter of their basic psychology? There surely could be a being that only thought of motion in the bare-bones terms I just sketched (“I was at home this morning but now I’m at the shops”), in which case Zeno’s paradox would not contradict anything this being actually believes. How do we distinguish between having a theory of something and merely accepting its existence? At the very least it is much harder to detect conflict between philosophy and basic belief than many philosophers have supposed. Are we reading more into ordinary belief than is really warranted? So-called common sense is not proto-philosophy. Philosophers have a tendency to over-intellectualize the thoughts of the non-philosophical thinker.[2]

[1] I believe the first person to make this point was Norman Malcolm, commenting on G.E. Moore.

[2] I plead guilty to this: I never questioned the rightness of the view here criticized for decades. I accepted that ordinary people think things that philosophers sometimes deny. I thought of people as mini philosophers. Many, no doubt, are, but not because it is built into what they already think. If I am right in what I say here, large tracts of philosophy are quite misguided. Philosophy is neither revisionary of ordinary belief nor in accordance with it; the two stand cognitively apart.

Qualities of Mind

Galileo, Descartes and Locke divided the physical world into primary and secondary qualities, thus carving out a place for the science of physics (the study of the primary qualities of matter). But they said nothing about the primary and secondary qualities of the mind, in the hope of carving out a place for the science of psychology (the study of the primary qualities of mind). What should we say about this question? The answer is not immediately clear: what would such qualities be? Someone might say that the answer is obvious: since secondary qualities are mental and primary qualities are non-mental, all the qualities of mind are secondary, none primary. The indicated conclusion might then be that there is no science of the mind comparable to physics, on account of a lack of proper subject matter for such a science. You can’t make science out of the merely subjective. Alternatively, and less drastically, it might be said that the relevant qualities belong to the body and are simply a special case of the familiar primary qualities of physical things. Bodies have shape, size, weight, number, and motion, so that we can identify bodily behavior as the proper subject matter of the science of psychology. The so-called mental attributes are all secondary qualities and therefore do not belong to the science of the mind, i.e., behavioral science. In either case, what we naively think of as the mind is consigned to the realm of the merely subjective—like color, sound, smell, etc. This realm contains no primary qualities for the simple reason that the mind does not have shape, size, weight, number, and motion—only the body does. Psychology can thus never be the same kind of science as physics (it might confine itself to introspective reports). It’s either behaviorism or nothing.

It seems to me that this is the exact opposite of the truth. It completely misconceives the concepts of primary and secondary qualities. True, the examples given by the originators of these concepts are as listed, but that is not the same as the underlying conception. That conception invites us to consider the qualities of things that constitute their intrinsic nature as opposed to qualities conferred on them from outside. When we switch subject-matter we must expect a different array of qualities. If we consider the primary qualities of numbers, we don’t expect to find the same qualities that apply to physical objects; we expect to find, and do find, mathematical qualities (being even, prime, motionless, weightless, imperceptible). In the case of the mind, then, the primary qualities will include whatever characterizes the intrinsic nature of the mind, as opposed to how we might subjectively represent it. And there is nothing to prevent us identifying these primary qualities as irreducibly mental. Thus, we might count as primary qualities of mind both phenomenological and propositional qualities (possibly also functional and computational qualities). These are what the mind inherently is, its inner constitution, its objective nature. The science of psychology will then study these kinds of qualities (properties, processes). Just as the standard primary qualities of physical objects comprise how objects are in themselves, independent of subjective viewpoint, so these primary qualities of minds (phenomenological and propositional) fix how minds are in themselves, independent of subjective viewpoint. The qualities that were declared extraneous to physics turn out to be central to psychology: colors, say, were transferred to the mind away from physical objects, but now these mental qualities become the primary qualities of psychology—what that science is really about. They are primary for psychology.

But this raises an interesting question: does the mind also have secondary qualities? What would that mean? It would mean that our ordinary ways of representing the mind introduce one perspective among many possible perspectives on the mind itself. Martians might see what we see as red objects as green, or taste our sweet things as bitter—might we likewise experience our own minds in a particular way possibly not shared by Martians? Might we introspect our minds via subjective representations of those minds? For example, might we introspect our experiences of red as experiences of green? This would be like experiencing the same wavelengths of light in two different subjective ways—as red or as green. The same mental primary quality (seeing red) might be experienced in two different ways—as an experience of red or as an experience of green. The mental quality might have two different dispositions to appear to a subject depending on his psychological make-up. That would be the analogue of the same physical object appearing in different ways to perceivers. If this were so, then that would be a genuine mental secondary quality. There would be a real distinction between mental primary qualities and mental secondary qualities. But surely there is no such thing, nor could there be. We are not at that kind of remove from our own minds; we don’t project qualities onto our minds in that way. I don’t have a subjective viewpoint onto my own mind, which might differ from other viewpoints onto the same (type of) mind. I project colors onto objects, but I don’t project experiences of red onto my own mind. Accordingly, there are no mental secondary qualities; all mental qualities are primary. The mind is not a composite of primary and secondary qualities, as physical objects are, but a collection of uniformly primary qualities, objectively possessed. The qualities of mind are never merely powers to produce impressions of those qualities in that mind or in other minds.

The absolute conception of the physical world supplied by physics involves abstracting away from the human perspective on the physical world; it is subtractive, invidious. But the absolute conception of the mind is not like that: it treats all attributes of mind as part of its subject matter. So far from ignoring subjectivity, it embraces it. In psychology the subjective is what is objective (real, absolute). And of course, this is true: what belongs to the mind objectively exists—though it may not exist “for physics”. If we try to mimic the formation of physics, carving out a subset of the qualities normally attributed to things, we end up with no proper subject matter for psychology (only behaviorism); but we should not attempt to duplicate this kind of movement of thought. There is really no primary/secondary distinction in psychology. Much the same is true in mathematics: there isn’t a collection of attributes of numbers found in common sense mathematics that needs to be jettisoned in order to put mathematics on a scientific footing—as it were, the colors and smells of numbers. There are just primary mathematical qualities. This is the right model for the science of psychology not physics. The metaphysical apparatus of primary and secondary qualities developed by Galileo, Descartes and Locke to put physics on a sound basis does not carry over to the psychological case. In particular, the subtractive impulse is out of place.[1]

[1] It is an indication of how undeveloped psychology was as a science in the seventeenth century that no one raised the question of whether psychology might admit of a primary/secondary distinction analogous to physics. As far as I know, the question has not been raised till now.

Knowledge of Primary and Secondary Qualities

We normally think we know the shapes and colors of things: I know, for example, that the cup in front of me is cylindrical and blue. But reflection casts doubt on this commonsense assumption, in two ways. First, there is the question of whether I really know that the cup is cylindrical, given that I might be under an illusion about this; skepticism undermines the claim to knowledge. The belief that the cup is cylindrical purports to record an objective property of the object, which is not logically entailed by any subjective evidence I have, such as that it looks cylindrical to me. Thus, the belief is not justified by anything immediately available to my mind, according to traditional skepticism, and hence is not a case of knowledge. On the other hand, and second, there is a problem about the claim that I know the color of the object, because it is not true that the cup is really blue—the cup is not objectively blue and hence this cannot be known.[1] Maybe there is something bluish going on in my mind, but the cup itself is not objectively blue, so the truth condition for knowledge isn’t satisfied. I might know that I am experiencing something blue, but it isn’t the cup—that thing existing in the mind-independent objective world. The justification condition is met just as well as in the shape case, for what that is worth, but the truth condition fails. So, I know neither that the cup is cylindrical nor that it is blue, but for different reasons. In the one case, the attribution is too objective to be known, because it exceeds my subjective evidence; in the other case, the attribution is too subjective to be known, since objects are not objectively colored. I cannot know the objective properties of things because of the gap between subjective and objective; and I cannot know that things have subjectively defined properties because they don’t, not really, not in themselves.

There is a way out of this pair of problems that has seemed attractive to many: bring shapes closer to the mind and move colors closer to external objects. Thus, we might maintain that shapes are dispositions to appear a certain way to subjects of experience, and colors are likewise dispositions of objects so to appear. We make the properties span the divide between subject and object. Then, we will have closed the epistemic gap between the objective nature of shape and the subjective experience of shape; and also linked the subjective nature of color to the external object. We will be able reliably to infer shape from appearance of shape, since shape is just a propensity to appear a certain way; and we will also link color to objects outside the mind, since colors just are dispositions of objects to produce sensory impressions. We will therefore have straddled the divide, making room for both sorts of knowledge. We put shapes partly in the mind, to which we have reliable access; and we put colors partly in the object, thus ensuring that our belief that objects are colored is true. We thereby save commonsense epistemology. This is a clever idea, and it satisfies a felt need, but it is really not plausible—it is a rickety contraption that fails to do justice to the facts. For, first, the real shapes of objects are not dispositions to appear thus and so: such a disposition could exist and yet the object not have the property in question, or the object could have a shape property that fails to generate the alleged disposition. Shapes characterize objective reality no matter how they may be disposed to affect the mind; they would be there even if there were no minds to interact with them. So, the epistemic gap remains; and it is not merely the product of some weird hyperbolic skepticism—it might be the result of serious science, as in certain physical theories (non-Euclidian geometry etc.). In the case of colors, the problem is that the appearance of color doesn’t square with the alleged metaphysics of color—colors don’t look like dispositions. Moreover, color perception and color belief actually attribute color to external objects in much the same way they attribute shape, i.e., non-dispositionally. It looks to us as if objects have intrinsic color properties that are not dependent on our minds. But they don’t actually have such properties, according to the secondary quality conception, so error is built into our beliefs about them. Accordingly, we don’t know them to have properties they really (truly) have. They are more subjective than our common sense suggests; so, we are in error about them. I don’t really know that my cup is cylindrical and blue, after all.

The problem arises because knowledge purports to be objective. It aspires to reach beyond itself into objective reality (same for perception and belief). It doesn’t purport to be merely subjective (I am speaking of knowledge of external objects not of properties of the mind itself, recognized as such). We don’t commonsensically think we know only what is going on inside us; we think we know facts about objects outside us. But this raises two objections: first, we are too epistemically ambitious, thinking we know more about reality than we have good reason to suppose; and second, we mistake the subjective for the objective, as when we project colors onto external objects. The aspiration to knowledge encourages us to objectivize, but this exceeds what we have a right to believe—we overdo our epistemic credentials. We underestimate the epistemic remoteness of primary qualities, and we overestimate the proximity of secondary qualities to external reality. We think the former are closer to our minds than they are, and we think the latter are closer to objects outside our minds than they are. So, we are more sanguine about our knowledge of these things than we ought to be. Upon examination, we see that we don’t really know the primary (objective) qualities of things, and we don’t know the true location of secondary qualities in the universe. Common sense is wrong about the status of both kinds of putative knowledge. We thus need to revise our ordinary beliefs about these things. What we should say is that we don’t know the objective reality of the primary qualities of nature, as a matter of our common sense (advanced science might know it better); and we don’t know that objects are colored, as they seem to common sense to be–we are under an illusion about that.

This has broader implications for the nature of knowledge in general. It sounds reasonable to separate human knowledge into two piles: absolute knowledge and relative knowledge. Some of our knowledge concerns reality as it exists independently of any sentient being, while some concerns matters of human interest and sensibility. But there are two objections to this kind of division: the absolute nature of reality is too far removed from our ordinary knowledge-acquiring abilities to count as genuinely known, though it undoubtedly exists; and the relative reality that reflects human nature is not conceived as such by our ordinary common sense—we tend to think it is more objective than it really is. We think our parochial representations are more absolute than they are, because knowledge aspires to generality—we over-objectivize because we take ourselves to be knowing beings in good standing. We are doubly overconfident epistemically: we think we know more about mind-independent reality than we do, and we think our merely relative knowledge is more robust than it is—more absolute, unconditional, and general. This is not mere dogmatism; it reflects the very nature of knowledge as objectively aspirational. The concept of knowledge itself makes us expect more generality than what naturally comes to us; we are suckers for the universal. To fully acknowledge the parochial nature of many of our beliefs would be to retreat from the enterprise of acquiring knowledge. The concept is too ambitious to fit what we are actually capable of achieving. Modesty recommends abandoning the concept, or scare-quoting it, or substantially qualifying it. You can’t, for example, keep on saying you know various moral truths when your official theory is that morality is an historically contingent relative human practice. You can’t have it both ways. There is thus no easy way out of the dilemma I have sketched: either claims to human knowledge are too ambitious, being concerned with the nature of reality absolutely considered; or they are falsely modest, because all knowledge aspires to universality in some measure. No one wants to say, “Oh, this is just something that we know; you may know something quite different”.  Knowledge and universality go together. Knowledge is undermined by relativity, but absoluteness is asking an awful lot. Both ideas are quixotic, intrinsically difficult to satisfy, arguably impossible of achievement.[2]

[1] I am assuming the classic distinction between primary and secondary qualities in this paper. I am concerned with the epistemological implications of this distinction, particularly as regards knowledge. For some background, see my The Subjective View (1983) in which I argue that primary qualities are subject to skepticism while secondary qualities are not. In that book I was too confident of the dispositional theory of color as consistent with common sense.

[2] If you find this paper hard to follow in places, don’t blame yourself; this is difficult stuff. It may help if I say that the figure of Bernard Williams lurks in the background.