How do you know you are right?

[Fortinbras Armstrong]

3. My immediate reaction on reading the OP was a rather sarcastic

"Congratulations on having discovered epistomology", but that was perhaps unkind.

Epistomology is concerned with two very basic questions, how do we know something? and what are the limits of our knowledge?

I shall pretty much ignore the second one, except to mention that the Heisenberg Uncertainty Principle and the Gödel Incompleteness Theorem demonstrate that there are some things which are inherently unknowable (I had a long argument on this point with my Introduction to Philosophy instructor -- I still say he was wrong).

The question "how do we know what we know?" is at the heart of quite a few subjects, such as psychology, intelligence work (yes, I mean spies -- there is an excellent discussion of the problem as it relates to intelligence in, of all places, the science fiction novel Torch of Freedom by David Weber), economics (Ludwig von Mises, whose political ideas I abhor, wrote an excellent book, Epistemological Problems of Economics), ethics (Thomas Aquinas in the Summa Theologica, I-II, question 76 considers the moral problems of acts done in ignorance at some length), the physical sciences and others.

I started writing an article on how we know things, but I got bogged down in a discussion of something called the Gettier Problem, and rather than post something really technical and difficult to follow, I thought I would just say a few brief words and let you look things up for yourself.