nothing that is worth knowing can be taught

Man can learn nothing unless he proceeds from the known to the unknown.

Without tact you can learn nothing.

Nobody teaches life anything.

It's useless to lecture a human.

No man is the wiser for his learning.

Those writings of mine aren't anything. There is nothing instructive in what I wrote.

No mathematician can give any meaning to language about matter, force, inertia, used in text-books of mechanics.

I have nothing to teach you that will help you to make a living. [as art teacher, advising his students]

What a teacher imparts by word of mouth is nothing in comparison with what he teaches us to get for ourselves from books.

There is no muse of philosophy, nor is there one of translation.

They who think they know all, learn nothing.

El asunto es muy sencillo: nadie aprende nada por escucharse a sí mismo hablar.

It is obvious that art cannot teach anyone anything, since in four thousand years humanity has learnt nothing at all.