Every man who has thought, knows not only how little he knows, but how little every other human being knows, and how ignorant, after all, the world must be.

And herein lies the tragedy of the age: not that men are poor, — all men know something of poverty; not that men are wicked, — who is good? not that men are ignorant, — what is Truth? Nay, but that men know so little of men.

Herein lies the tragedy of the age: not that men are poor, — all men know something of poverty; not that men are wicked, — who is good? not that men are ignorant, — what is Truth? Nay, but that men know so little of men.

Man's knowledge, save before his fellow man,
Is ignorance—his widest wisdom folly.

There are many who know many things, yet are lacking in wisdom.

The self-taught man seldom knows anything accurately, and he does not know a tenth as much as he could have known if he had worked under teachers;

He who knows best knows how little he knows.

Individual humans know embarrassingly little about the world, and as history has progressed, they have come to know less and less. A hunter-gatherer in the Stone Age knew how to make her own clothes, how to start a fire, how to hunt rabbits, and how to escape lions. We think we know far more today, but as individuals, we actually know far less. We rely on the expertise of others for almost all our needs.

In the popular arena, one can tell … that the average man … imagines that an industrious acquisition of particulars will render him a man of knowledge. With what pathetic trust does he recite his facts! He has been told that knowledge is power, and knowledge consists of a great many small things.

The title wise is, for the most part, falsely applied. How can one be a wise man, if he does not know any better how to live than other men? — if he is only more cunning and intellectually subtle?

That life keeps teaching me how little I actually know. I used to think I was going to die wise, and now the one wisdom I have is I know very little.

The knowledge of an unlearned man is living and luxuriant like a forest, but covered with mosses and lichens and for the most part inaccessible and going to waste; the knowledge of the man of science is like timber collected in yards for public works, which still supports a green sprout here and there, but even this is liable to dry rot.

Much learning shows how little mortals know;
Much wealth, how little worldlings can enjoy.

What a wise man knows seems so plain and simple to himself that he easily makes the mistake of thinking it to be so for others.