This will be another post about two apparent philosophical opposites. And just like my considerations of moral realism and anti-realism; consequentialism and deontology; and free will and determinism, I will be arguing that there is to some degree a worthwhile common ground on which philosophers can safely tread. As you’ve probably noticed, the apparent opposition for this article is that between two topics in epistemology (the study of knowledge), which both confront the question of knowledge’s basis and origin: rationalism and empiricism.
Roughly speaking, rationalists hold that some or all of our knowledge is known independent of and prior to sense experience, whereas empiricists hold that some or all of our knowledge comes solely from sense experience. For a far-reaching and specific introduction to these topics in epistemology, see this encyclopedia entry; for my (hopefully somewhat pithier) thoughts on these topics, read on.
David Hume, Empiricism, and Rationalism:
There are different kinds of rationalism, generally affirming that one or more of the following things exists and constitutes a priori knowledge: intuition, innate knowledge, innate concepts. Intuition is probably the most popular rationalist topic, but is also the one with the largest suite of accompanying complications and problems. To take just one example, many would contend that this form of rationalism seems to leave off mid-argument, declaring itself to have found the source of knowledge without justifying its claim, or else, as in the famous cases of the Platonic soul-memory of the forms and the Cartesian circle, providing an endpoint that merely begs the question. I will come back to the other most salient rationalist topics below.
Strict empiricists like Thomas Hobbes, on the other hand, are unlikely to affirm that anything that can be termed knowledge could also be called innate. Instead, empiricists would say that knowledge comes from a confluence of experience, education, and observation. So where, then, is the common ground alluded to at the outset? To see it, I would first quote an influential passage on epistemology by early modern empiricist David Hume:
All the objects of human reason or inquiry may naturally be divided into two kinds, to wit, “Relations of Ideas,” and “Matters of Fact.” Of the first are the sciences of Geometry, Algebra, and Arithmetic, and, in short, every affirmation which is either intuitively or demonstratively certain. That the square of the hypotenuse is equal to the square of the two sides is a proposition which expresses a relation between these figures. That three times five is equal to half of thirty expresses a relation between these numbers. Propositions of this kind are discoverable by the mere operation of thought, without dependence on what is anywhere existent in the universe. Though there never were a circle or triangle in nature, the truths demonstrated by Euclid would forever retain their certainty and evidence. Matters of fact, which are the second objects of human reason, are not ascertained in the same manner, nor is our evidence of their truth, however great, of a like nature with the foregoing. The contrary of every matter of fact is still possible, because it can never imply a contradiction and is conceived by the mind with the same facility and distinctness as if ever so conformable to reality. (Hume 40)
Hume is writing in the context of an ongoing discussion in epistemology concerning external reality. On the topic of external reality, Hume is clarifying that strict rationalists are over-stepping their reach, for logic and reason divorced from sense experience can not alone prove—or even provide evidence for—the truth of a proposition concerning the external world. A posteriori premises are needed for a posteriori conclusions.
Notice, however, that Hume gives logic and reason their place. Hume sees reason, however conceived, as the form of inquiry that deals in relations of ideas. The reasoning faculty is that which mediates among concepts, especially when those concepts are themselves metaphysical. Indeed, I would go even farther than Hume by granting that humans have innate—and thus a priori—knowledge, but I would follow (in the big picture, if not in the particulars) Peter Carruthers’ account of this knowledge as a result of human evolution by natural selection.
Much as I have previously written of humanity’s inescapable perception of free will, so humanity seems to also have an inescapable perception of innate knowledge. This knowledge is the form taken by a functional, structural correspondence among genetics, behaviors, thoughts, and worldly utility. Such knowledge does not come from empirical verification, but it is subject to empirical verification. In this way, there can be coexistence and interplay in epistemology between rationalism and empiricism.
William James, Pragmatism, and Epistemology:
This is fallible knowledge, evolved knowledge, and best-fit knowledge. In a sense, it is pragmatic knowledge. I certainly do not follow Descartes’ steps—after his monumental, brilliantly rendered first two meditations come to a close—when he proceeds into an account of absolute, infallible a priori truths. William James presents the following harshly sarcastic words, as his impression of hardline rationalists responding to pragmatism:
Pragmatism is uncomfortable away from facts. Rationalism is comfortable only in the presence of abstractions. This pragmatist talk about truths in the plural, about their utility and satisfactoriness, about the success with which they ‘work,’ etc., suggests to the typical intellectualist mind a sort of coarse lame second-rate makeshift article of truth. Such truths are not real truth. Such tests are merely subjective. As against this, objective truth must be something non-utilitarian, haughty, refined, remote, august, exalted. It must be an absolute correspondence of our thoughts with an equally absolute reality. It must be what we ought to think unconditionally. The conditioned ways in which we do think are so much irrelevance and matter for psychology. Down with psychology, up with logic, in all this question! (James)
As you could probably infer from the other posts in this series, I would have no end of disagreement with William James over the relationship between his pragmatic philosophical methodology and the sophistic beliefs which he was wont to justify with that methodology at times. But James would be fully ready to accept that disagreement, for he affirms in that quoted paper as elsewhere that pragmatism is a method or means, and is not itself a set of beliefs. And the ways in which James here contends that his epistemology differs from hardline rationalism, however disparaging, seem highly apt.
James’ defense of tentative, realistic, and practical testing of beliefs and practices is one that I respect. What I like best about his approach is its implicit compromise between empiricism and rationalism, wherein neither source of knowledge is taken as the only, the best, or the infallible kind of epistemology. It encompasses the likelihoods of deception and fallibility. The Jamesian informality of pragmatism’s formulation, however, leaves something to be desired.
Moreover, Anthony Kenny rightly points out that even some of the biggest names in historical rationalism, such as Descartes, and some of the biggest names in historical empiricism, such as Locke, share far more premises in common than either group readily understood in the early modern period:
On the topic of innate ideas, the arguments of Locke and Descartes largely pass each other by. Descartes argues that experience without an innate element is an insufficient basis for scientific knowledge; Locke insists that innate concepts without experience cannot account for the knowledge we have of the world. Both contentions may well be correct. (Kenny 600)
My own approach to the various truths I have been born with, been raised into, been taught, or observed is closer to, on the one hand, ideas which have as a primary ancestor pragmatism—such as the past century’s often-misunderstood systems in the philosophy of science—and, on the other hand, phenomenology. A topic for another day would be the particulars of how these philosophies inform my epistemology more generally. Next week’s article will consider a topic closely related to rationalism and empiricism: the is-ought problem.
 It should be stated that, for the purposes of clarity and simplicity in this article, the question of whether one can actually access the reality which would provide that empirical verification has been bracketed, or left out. That is what is meant by the opaque reference to phenomenology that appears in the conclusion of this article: that what one is actually referencing when gathering empirical data are phenomena—and, of course, not necessarily noumena.