One must credit an hypothesis with all that has had to be discovered in order to demolish it.

There are two times in a man's life when he should not speculate: when he can't afford it, and when he can.

It is theory that decides what can be observed.

A speculator is a man who observes the future, and acts before it occurs.

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Theories are always very thin and insubstantial, experience only is tangible.

The temptation to form premature theories upon insufficient data is the bane of our profession.

When speculation has done its worst, two and two still make four.

You must stick to your conviction, but be ready to abandon your assumptions.

We now have a whole culture based on the assumption that people know nothing and so anything can be said to them.

Your assumptions are your windows on the world.

Scrub them off every once in a while, or the light won't come in.

A young man is a theory, an old man is a fact.

In order to shake a hypothesis, it is sometimes not necessary to do anything more than push it as far as it will go.

I never guess. It is a shocking habit -- destructive to the logical faculty.

Some theories are good for nothing except to be argued about.

What most people don't seem to realize is that there is just as much money to be made out of the wreckage of a civilization as from the upbuilding of one.

Let us work without theorizing, 'Tis the only way to make life endurable.

The narrower the mind, the broader the statement.

No theory is good unless it permits, not rest, but the greatest work.

No theory is good except on condition that one use it to go on beyond.

Theories that go counter to the facts of human nature are foredoomed.

Even for practical purposes theory generally turns out the most important thing in the end.

A theory is no more like a fact than a photograph is like a person.

Delight at having understood a very abstract and obscure system leads most people to believe in the truth of what it demonstrates.

Socrates thought and so do I that the wisest theory about the gods is no theory at all.

I never attempt to make money on the stock market.

I buy on the assumption that they could close the market the next day and not reopen it for five years.

I do not like the word tolerance, but could not think of a better one.

Tolerance implies a gratuitous assumption of the inferiority of other faiths to one

If we all worked on the assumption that what is accepted as true is really true, there would be little hope of advance.

Most people assume that women are responsible for households and child care.

Most couples operate that way - not all. That fundamental assumption holds women back.

Society cannot continue to disable themselves through their need to categorize people or make assumptions as to another individual's abilities.

Begin challenging your own assumptions.

Your assumptions are your windows on the world. Scrub them off every once in awhile, or the light won't come in.

Another key element of human ecology is the inviolability of human life, especially at its beginning and its end. The Holy See insistently proclaims that the first and most fundamental of all human rights is the right to life, and that when this right is denied all other rights are threatened. The assumption that abortion and euthanasia are human rights deserving legislative sanction is seen by the Holy See as a contradiction which amounts to a denial of the human dignity and freedom which the law is supposed to protect. A society will be judged on the basis of how it treats its weakest members; and among the most vulnerable are surely the unborn and the dying.

Treat with utmost respect your power of forming opinions, for this power alone guards you against making assumptions that are contrary to nature and judgments that overthrow the rule of reason.

There never comes a point where a theory can be said to be true.

The most that one can claim for any theory is that it has shared the successes of all its rivals and that it has passed at least one test which they have failed.

It is not enough for theory to describe and analyze, it must itself be an event in the universe it describes. In order to do this theory must partake of and become the acceleration of this logic. It must tear itself from all referents and take pride only in the future. Theory must operate on time at the cost of a deliberate distortion of present reality.

To insure the adoration of a theorem for any length of time, faith is not enough, a police force is needed as well.

The world can doubtless never be well known by theory: practice is absolutely necessary; but surely it is of great use to a young man, before he sets out for that country, full of mazes, windings, and turnings, to have at least a general map of it, made by some experienced traveler.

Another great evil arising from this desire to be thought rich;

or rather, from the desire not to be thought poor, is the destructive thing which has been honored by the name of speculation; but which ought to be called Gambling.

Creating a new theory is not like destroying an old barn and erecting a skyscraper in its place. It is rather like climbing a mountain, gaining new and wider views, discovering unexpected connections between our starting points and its rich environment. But the point from which we started out still exists and can be seen, although it appears smaller and forms a tiny part of our broad view gained by the mastery of the obstacles on our adventurous way up.

A theory is the more impressive the greater is the simplicity of its premises, the more different are the kinds of things it relates and the more extended the range of its applicability.

Speculation is only a word covering the making of money out of the manipulation of prices, instead of supplying goods and services.

Choose an attitude of wonderment, taking in all that is being said without assuming you already know what the speaker is talking about. Let go of jumping ahead to finish his or her thoughts. In order to learn you have to risk change...changing your mind!

The wise man regulates his conduct by the theories both of religion and science.

But he regards these theories not as statements of ultimate fact but as art-forms.

If the world were good for nothing else, it is a fine subject for speculation.

Unaware of the absurdity of it, we introduce our own petty household rules into the economy of the universe for which the life of generations, peoples, of entire planets, has no importance in relation to the general development.

If there were no bad speculations there could be no good investments;

if there were no wild ventures there would be no brilliantly successful enterprises.

Every theory is a self-fulfilling prophecy that orders experience into the framework it provides.

Everything that explains the world has in fact explained a world that does not exist, a world in which men are at the center of the human enterprise and women are at the margin helping them. Such a world does not exist -- never has.

The world always makes the assumption that the exposure of an error is identical with the discovery of truth--that the error and truth are simply opposite. They are nothing of the sort. What the world turns to, when it is cured on one error, is usually simply another error, and maybe one worse than the first one.

The Theory of Groups is a branch of mathematics in which one does something to something and then compares the result with the result obtained from doing the same thing to something else, or something else to the same thing.

Theoretical principals must sometimes give way for the sake of practical advantages.

Good tests kill flawed theories; we remain alive to guess again.