I recently read the SEP article "Foundationalist Theories of Epistemic Justification" and was quite disappointed by the protracted discussion, not of Foundationalism, but of claims of infallibility. We read:

Aristotle argued that “not all knowledge is demonstrative” (i.e., not all knowledge is based on an argument from other things known), and that some knowledge must be “independent of demonstration” (Posterior Analytics, I.3). — Ali Hasan and Richard Fumerton

After that the article goes off on multiple tangents that seem not to touch on the central issue.

Aristotle's claim is simple and straight forward: we can't prove everything, so we have to accept some judgements without proof. One can show this with an infinite regress argument, or simply reflect that life is too short to prove an unlimited number of claims. As far as I know, Aristotle never claimed to be infallible, or even that one could not question and discuss the grounds for accepting fundamental premises. Indeed, he does so, but considering how we form judgements and discussing the consequences of rejecting the principles of logic.

Aristotle founded a number of sciences, including marine biology and mathematical physics, and he insisted that his students get their hands dirty doing dissections. It seems to me that he did philosophy in the same way, by reflecting on the reality he encountered, not the world he imagined -- as did 19th century German metaphysicians. He saw that we learn about reality via sense data and, in De Anima, provided an unparalleled analysis of what must happen for physical sensation to yield intellectual understanding.

Clearly, human beings are fallible. So it is an enormous error to begin philosophizing by seeking an infallible basis for human knowledge, as Descartes did. He, and others, made divine omniscience the paradigm case of human knowing. We are not God, and will never know as God does. Thinking that we do, or ought to, is what I call the Omniscience Fallacy. Not only are we subject to errors of judgement, but our brains can only maintain 5-9 “chunks” of information in working memory. (D. A. Broadbent, “The Magical Number Seven After Fifteen Years” in Alan Kennedy and Alan Wilkes, eds., Studies in Long-Term Memory. (New York: Wiley, 1975): 3-18.) So, we do not know anything exhaustively.

It is consequence of this second observation, of our limited representational capacity, that we must employ the stupid human trick of abstraction. When we encounter a complex situation, and all situations are complex, we must focus on certain aspects, on selected notes of intelligibility, to the neglect of others. The result is an abstraction. Abstractions, then, scale the complexity of reality down to our limited human representational capacity. We invariably wind up with a projection of reality -- a dimensionally diminished map.

Alfred North Whitehead recognized this in Science and the Modern World and pointed out an all too common and unrecognized error, which he called "The Fallacy of Misplaced Concreteness" (p. 11). The fallacy is mistaking our abstractions with the reality from which they are abstracted. As I pointed out in discussing the Hard Problem of Consciousness on this forum, this is the basis of both reductionism and physicalism.

Further, all knowing is a subject-object relation. There is no knowing without a knowing subject and a known object. Consequently, it is foolish (an instance of Misplaced Concreteness) to speak of "purely objective" knowledge as though it were possible for humans. Our encounter with reality is relational -- shaped not only by the nature of what we encounter, but also by our human capacity for encounter, with all of its limitations. So, we can never know reality as "it is," as God does, but only as it relates to us.

Still, this is enough. While all we can know is how reality relates to us, that is all we need to know -- for we only deal with reality in relation to us. How else could we deal with it?

So, we come to the question of truth. Corherrentist theories deal with something of no concern to humans, as we are concerned with how to live in the world, and that requires us to be in relation to what we call "reality." So, the only kind of truth that matters is one that reflects the human relation to reality. How should we characterize that relation?

Truth is not correspondence to reality. Why? First, because our knowledge is not exhaustive, but leaves an untold amount behind. It is only a diminished projection of what we encounter. Second, because we do not and cannot know reality as it is, but only as it relates to us. (While relations reflect the nature of the relata, they are not the natures of the relata.) Of course, we want truth to reflect our relation to reality, but reflecting our relation to reality is not reflecting reality in se.

The medieval Scholastic defined truth asadaequatio intellectus et rei (the approach to equality of intellect and reality). The important point here, is that, despite numerous mistranslations, adaequatio does not mean "equality" (aequatio), but "approach to equality." Thus, the definition does not demand correspondence as a requirement of truth.

If only an approach to equality is required, the question arises: "How close an approach?" Let me suggest that the answer is context-sensitive, and suggested by the English cognate of adaequatio, "adequate." To be true, our judgements must be adequate to the context under consideration. Remembering that what we know is not exhaustive and based on an abstractive process, that our judgement will be adequate if what we ignored in our abstractions is irrelevant to our present endeavor.

For example, I do not think I was lying when I taught freshmen engineering students Newtonian physics without fully explaining how relativistic quantum physics falsified it. Why? Because what I taught them was adequate to their needs. Those who would need more precise physics would take other courses to learn it. We can never present all that we know, but we can speak the truth by presenting something adequate to the needs of our audience.

In sum, philosophy can only deal with human knowledge, because, however limited, it is the only knowledge we have. It begins by accepting experience, not as infallible, but as the only raw material that we have to reflect upon.