The risk of paying too high a price for good-quality stocks is not the chief hazard for the thoughtful, enterprising investor — his chief hazard is the adoption of unsound principles or inapplicable methods under conditions of excitement and stress.

It is not the insurrections of ignorance that are dangerous, but the revolts of intelligence.

The demand of the human intellect is for a world in which something is permanently true. Science gives us a world in which everything is provisionally true — which is not at all the same thing.

We are reluctant to believe that the world we see is not the whole world. Yet the history of knowledge is largely the history of such reluctance being overcome.

The ability to destroy your ideas rapidly instead of slowly when the occasion is right is one of the most valuable things you can have. You have to work hard on it. Ask yourself what are the arguments on the other side. It's bad to have an opinion you're proud of if you can't state the other side better than your opponents.

We are apt to think that our ideas are the spontaneous product of the mind working upon experience; but in truth our ideas are largely the inheritance of past thought, and the experience upon which they work is itself colored by inherited assumptions.

The truth is that we never know for certain about anything. The degree of assurance we feel about any proposition is not a measure of its truth, but a measure of our familiarity with the evidence bearing on it.

Every act of conscious learning requires the willingness to suffer an injury to one's self-esteem. That is why young children, before they are aware of their own self-importance, learn so easily.

The chains of habit are too light to be felt until they are too heavy to be broken. Most people don't recognize the institutional imperative at work — the tendency of organizations to mindlessly imitate whatever peers are doing, regardless of whether it makes sense.

It is not what the man of science believes that distinguishes him, but how and why he believes it. His beliefs are tentative, not dogmatic; they are based on evidence, not on authority or intuition.

We are all of us the worse for too much solitude. A man who shuts himself up from the world falls into an exaggerated estimate of his own importance, and loses the power of measuring himself by his fellows.

The universe is under no obligation to make sense to you. But stranger still is the fact that it does — partially, provisionally, and always at the cost of uprooting what we thought we already knew.

Risk means more things can happen than will happen. The dangerous investor is not the one who doesn't know what will happen, but the one who doesn't know what he doesn't know.

The fact that an opinion has been widely held is no evidence whatever that it is not utterly absurd; indeed in view of the silliness of the majority of mankind, a widespread belief is more likely to be foolish than sensible.

The art of being wise is the art of knowing what to overlook.

The mind, in short, works on the data it receives very much as the sculptor works on his block of stone. In a sense the statue stood there from eternity. But there were a thousand different ones beside it in the same stone, and the sculptor alone is to thank for having extricated this one from the rest.

The difficulty lies not in the new ideas, but in escaping from the old ones, which ramify, for those brought up as most of us have been, into every corner of our minds.

We accept the verdict of the past until the need of the present voices a demand for change; and even then we rarely have the courage to deny that the past was right, we merely claim that it was right for another age.

The mind is furnished with a set of instincts which seek out certain kinds of phenomena and ask for explanations of certain kinds of things. Any answer to a question which does not ask or explain the right kind of thing will be philosophically frustrated and dull.

The best thing for your own mind is to be exposed relentlessly to smart people who disagree with you.

The mind does not work by way of ideas, but by way of passionate preferences; we do not see nature, we see our idea of nature.

The biggest investing errors come not from companies that fail, but from companies that succeed in ways you didn't anticipate. You prepare for the future by studying how the past was different from what people expected.

The mind is furnished with a set of instincts which seek out certain kinds of phenomena and are angered by their absence and immediately go in search of them.

The sign of a first-rate intelligence is the ability to hold two opposed ideas in the mind at the same time, and still retain the ability to function.

The big question about artificial intelligence is not whether machines can think, but whether humans will stop thinking and let the machines do it for them.

The mind is furnished with a set of instincts which seek out certain kinds of phenomena and are angered by their absence and appalled by alien forms; which love them when found, but will have none of them when not directly forced upon us.

The mind of a thoroughly well-informed man is a dreadful thing. It is like a bazaar overcrowded with cheap wares, all one's attention is perpetually distracted by some new and startling suggestion.

The best way to think about the future is not by extrapolating the past, but by understanding incentive structures and what they reward. Most people get this backwards.

The human mind is a dark forest, full of wild life and monsters. We do not know what we are, we can only see small lights in the forest of our unconsciousness, as it were luminous, phosphorescent flowers and night-blossoms.

The mind of a thoroughly well-informed man is a dreadful thing. It is like a bazaar overcrowded with all sorts of goods, each clamoring for attention.

The investor of today does not profit from yesterday's growth. You must study where the world is heading, not where it has been. Most people are heavily invested in the past.