Anything worth knowing cannot be understood by the human mind.

Objection to scientific knowledge: this world doesn't deserve to be known.

nothing that is worth knowing can be taught

Anything new, anything worth doing, can't be recognized.

Absolute proof of absolute knowledge is impossible.

Information is not knowledge.

Knowledge is knowing that we cannot know.

[K]nowledge that is not Infallible is not certain knowledge.

Nothing puts a greater obstacle in the way of the progress of knowledge than thinking that one knows what one does not yet know.

Abundance of knowledge does not teach men to be wise.

Knowledge is of no value unless you put it into practice.

Integrity without knowledge is weak and useless, and knowledge without integrity is dangerous and dreadful.

Not ignorance, but ignorance of ignorance is the death of knowledge.

Knowledge ceases to be wisdom when one has no method for making sense or use of what one learns.