Epistemologists are philosophers who are interested in questions such as whether it is possible to have knowledge, what kind of knowledge there is, and how people come to know things.
One of the first philosophers to make a clear statement on these questions was Xenophanes (570–470 BC). The following saying was, and still is, famous:
- "Certain truth has no man... for even if he ever succeeds in saying what is true, he will never know it".
This is an early kind of skepticism.
- Knowing how vs. knowing that: This was an idea of Gilbert Ryle. Moral questions, for example, may come down to knowing how to behave. Science could be about knowing that something is the case.
- Rational vs. empirical knowledge: Rational knowledge (if it exists) is knowledge built up from a person's internal thought. Empirical knowledge is built up from what is received through the senses.
- Error: Knowledge cannot err vs. the possibility of making mistakes is an essential part of knowledge (Ludwig Wittgenstein).
There are other debates of this kind.
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