Nothing in the world is more dangerous than sincere ignorance.

The world is full of obvious things which nobody by any chance ever observes. Where do you think that I have been?" "A fixture also." "On the contrary, I have been to Devonshire." "In spirit?" "Exactly. My body has remained in this arm-chair and has, I regret to observe, consumed in my absence two large pots of coffee and an incredible amount of tobacco.

I can see nothing," said I, handing it back to my friend. "On the contrary, Watson, you can see everything. You fail, however, to reason from what you see. You are too timid in drawing your inferences.

a man's brain originally is like a little empty attic, and you have to stock it with such furniture as you choose. A fool takes in all the lumber of every sort that he comes across, so that the knowledge which might be useful to him gets crowded out, or at best is jumbled up with a lot of other things so that he has a difficulty in laying his hands upon it.

Are you well up in your Jean Paul?

This is the case with many learned persons; they have read themselves stupid.

reading is equivalent to thinking with someone else's head instead of with ones own

Truth that has merely been learned is like an artificial limb, a false tooth, a waxen nose; it adheres to us only because it is put on. But truth acquired by thought of our own is like a natural limb; it alone really belongs to us.

You can apply yourself voluntarily to reading and learning, but you cannot really apply yourself to thinking: thinking have to be kindled, as a fire is by a draught, and kept going by some kind of interest in its object, which may be an objective interest or merely a subjective one.

an intellect that positively excels even in one single direction is among the rarest of natural phenomena.

Students, and learned persons of all sorts and every age, aim as a rule at acquiring information rather than insight. They pique themselves upon knowing about everything—stones, plants, battles, experiments, and all the books in existence. It never occurs to them that information is only a means of insight, and in itself of little or no value.

You always learn from observing. You have to pick things up nonverbally because people will never tell you what you're supposed to know. You have to get it for yourself: whatever it is that you need in order to survive. You become strong by doing the things you need to be strong for. This is the way genuine learning takes place.