Topics Knowledge

Question How do you know that you know something? Isn't everything a perception? Even science assumes that the world is real and the senses convey truth about the world--and perhaps even more. If everything is perception, then how does one leap to the level of finally "knowing" something.

Accepted:
December 7, 2005

Comments

Ahh, you have raised one of the oldest questions in epistemology (the theory of knowledge). If you are seeking some unassailable foundation for all of your knowledge, then for the reasons that motivate your question, you are going to fall short. For any foundations you propose can be queried for justification: Why believe them? If they have no justification, they don't constitute knowledge; if they do, you are off on a regress.

Or, to put it a different way, if you had a criterion that would tell you when you know something and when you don't, you'd have to justify that criterion. But if you used that criterion itself as the justification, you would argue in a circle, and if you needed another criterion, you are off on a regress.

Sextus Empiricus, in THE OUTLINES OF PYRRHONISM and AGAINST THE LOGICIANS among other texts, developed such arguments in great detail. Nagarjuna, in VIGRAHAVYAVARTANI, develops interesting variations in an Indina context. He argues that we can only test our means of gaining knowledge by showing that they get us to true claims, and that we can only test those claims by our means of knowledge, and so that knowledge can never be ultimately grounded. In China, the Daodeching and some of the chapters of the Chuangtze develop these ideas in still different ways. As you can see, you are not alone in asking these questions, and they have a very ancient pedigree.

As many of these philosophers suggested, and as philosophers such as David Hume (TREATISE OF HUMAN NATURE) and Ludwig Wittgenstein (ON CERTAINTY) argued more directly, a way out of these worries is to pay closer attention to what you really mean by "knowledge." If you mean something that is absolutely grounded on unassailable, self-justifying foundations through unassailable, self-justifying reasoning, you mean something incoherent. It would be like asserting that knowledge requires the possession of a round square. Instead, pay attention to the conditions under which we credit others and ourselves with knowledge, and the role that concept plays in our theoretical lives, and you will see that knowledge always involves the presence of enough justification for the relevant context, and that the kind and degree of justification we demand varies from context to context, and is never absolute like that. We can know because to know is not as hard as it sounds, and is not as secure as it sounds, either.

You can't think without thinking, but fortunately it doesn't follow that you can only think about thinking. There are wonderful philosophical questions about how we perform the feats of representing things in the wolrd and of distinguishing correct from incorrect representations; but the the undeniable fact that all our mental representations are indeed mental does not show these feats to be impossible.