Richard P. Feynman Quotes

The theory must not contradict empirical facts.

I believe there is no philosophical high-road in science, with epistemological signposts. No, we are in a jungle and find our way by trial and error, building our road behind us as we proceed.

The best and safest way of philosophising seems to be, first to enquire diligently into the properties of things, and to establish those properties by experiences [experiments] and then to proceed slowly to hypotheses for the explanation of them. For hypotheses should be employed only in explaining the properties of things, but not assumed in determining them; unless so far as they may furnish experiments.

All science is based on models, and every scientific model comprises three distinct stages: statement of well-defined hypotheses; deduction of all the consequences of these hypotheses, and nothing but these consequences; confrontation of these consequences with observed data.

That said, ID does not qualify as science because it gives us nothing to test or measure. Science requires replicable tests involving measurable variables.

Hypotheses should be subservient only in explaining the properties of things but not assumed in determining them, unless so far as they may furnish experiments.

Not as a demonstrated natural law, but as a working hypothesis.

We would be in a nasty position indeed if empirical science were the only kind of science possible.

The criterion of the scientific status of a theory is its falsifiability, or refutability, or testability.

To say that prediction is the purpose of a scientific theory is to confuse means with ends. It is like saying that the purpose of a spaceship is to burn fuel. ... Passing experimental tests is only one of many things a theory has to do to achieve the real purpose of science, which is to explain the world.

It is generally believed that our science is empirical and that we draw our concepts and our mathematical constructs from the empirical data. If this were the whole truth, we should, when entering into a new field, introduce only such quantities as can directly be observed, and formulate natural laws only by means of these quantities.

A theory can be proved by experiment; but no path leads from experiment to the birth of a theory.

Science, incidentally, not only ignores the question of indwelling 'essences' by looking instead at measurable relationships, but science also does not agree that knowledge is obtained through Rothbard's Medieval 'investigation by a reason,' i.e., by inventing definitions and then deducing what your definitions implicitly assumed.

A theory is a good theory if it satisfies two requirements: it must accurately describe a large class of observations on the basis of a model that contains only a few arbitrary elements, and it must make definite predictions about the results of future observations.

The truth of a theory can never be proven, for one never knows if future experience will contradict its conclusions.

It appears that anything you say about the way that theory and experiment may interact is likely to be correct, and anything you say about the way that theory and experiment must interact is likely to be wrong.

Experiment is fundamentally only induced observation.

The principle of science, the definition, almost, is the following: The test of all knowledge is experiment. Experiment is the sole judge of scientific "truth." But what is the source of knowledge? Where do the laws that are to be tested come from? Experiment, itself, helps to produce these laws, in the sense that it gives us hints. But also needed is imagination to create from these hints the great generalizations--to guess at the wonderful, simple, but very strange patterns beneath them all, and then to experiment to check again whether we have made the right guess.

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.

Science is a combination of theory and experiment and the two together are how you make progress.

It is a very long and very difficult road from a fact to a conclusion. But it is a million times longer from a theory to a fact.

To construct a scientific theory from the data and to be able to recognize that it is a reasonable theory is possible only if there are some very sharp restrictive principles that lead you to go in one direction and not in another direction. Otherwise, you wouldn't have science at all, merely randomly chosen hypotheses.

It cannot be that axioms established by argumentation should avail for the discovery of new works, since the subtlety of nature is greater many times over than the subtlety of argument. But axioms duly and orderly formed from particulars easily discover the way to new particulars, and thus render sciences active.

They have never affirm'd any thing, concerning the cause, till the trial was past: whereas, to do it before, is a most venomous thing in the making of Sciences: for whoever has fix'd on his Cause, before he has experimented; can hardly avoid fitting his Experiment, and his Observations, to his Own Cause, which he had before imagin'd; rather than the Cause to the Truth of the Experiment itself. Referring to experiments of the Aristotelian mode, whereby a preconceived truth would be illustrated merely to convince people of the validity of the original thought.

In order that the facts obtained by observation and experiment may be capable of being used in furtherance of our exact and solid knowledge, they must be apprehended and analysed according to some Conceptions which, applied for this purpose, give distinct and definite results, such as can be steadily taken hold of and reasoned from.