Science, great, mighty and in the end unerring, science has fallen into many errors - errors which have been fortunate and useful rather than otherwise, for they have been the steppingstones to truth.

Science, my boy, is made up of mistakes; but of mistakes which lead to the discovery of truth.

Science, my lad, has been built upon many errors; but they are errors which it was good to fall into, for they led to the truth.

The history of science is a long unbroken chain of elabo­ration, deviation, and rectification, re-creation, followed by reassessment, renewed deviation and rectification, and re­newed creation. It has been a long, arduous course, and we have hardly begun. It adds up to a mere two thousand years, interspersed with long arid stretches. The living world is hundreds of thousands of years old and will probably go on existing for many centuries to come. Life is constantly mov­ing forward t never backward. Life is growing ever more complex and its tempo is accelerating. Honest pioneer work in the field of science has always been and will continue to be, life's pilot. On all sides, life is surrounded by hostility. This puts us under an obligation.

History of science played a very important role for me. Before I knew well how to do an experiment, I knew why Joliot has missed the neutron, why his wife missed the fission, why they succeeded in having artificial radioactivity, and even why they almost missed the other things, by doing very nice experiments, but didn't come to the conclusion. That is science. Science is doubt, is research. It is not something which is – and that is the danger of teaching – which is too academic and which the people explain you it is like the logic thing that comes out of the computer, which is not true. You have intuition, you have passion.

Scientists make mistakes. Accordingly, it is the job of the scientist to recognize our weakness, to examine the widest range of opinions, to be ruthlessly self-critical. Science is a collective enterprise with the error-correction machinery often running smoothly.

Science, my boy, is made up of mistakes, but they are mistakes which it is useful to make, because they lead little by little to the truth.

Science, my lad, is made up of mistakes, but they are mistakes which it is useful to make, because they lead little by little to the truth.

Science, my lad, is made up of mistakes, but they are mistakes which it is useful to make, because they lead little by little to the truth.

The history of science should not be an instrument to defend any kind of social or philosophic theory; it should be used only for its own purpose, to illustrate impartially the working of reason against unreason, the gradual unfolding of truth, in all its forms, whether pleasant or unpleasant, useful of useless, welcome or unwelcome.

But the history of science — by far the most successful claim to knowledge accessible to humans — teaches that the most we can hope for is successive improvement in our understanding, learning from our mistakes, an asymptotic approach to the Universe, but with the proviso that absolute certainty will always elude us. We will always be mired in error. The most each generation can hope for is to reduce the error bars a little, and to add to the body of data to which error bars apply. The error bar is a pervasive, visible self-assessment of the reliability of our knowledge.

Men of science have made abundant mistakes of every kind; their knowledge has improved only because of their gradual abandonment of ancient errors, poor approximations, and premature conclusions.

Scientists, like other human beings, have their hopes and fears, their passions and despondencies—and their strong emotions may sometimes interrupt the course of clear thinking and sound practice. But science is also self-correcting. The most fundamental axioms and conclusions may be challenged. The prevailing hypotheses must survive confrontation with observation. Appeals to authority are impermissible. The steps in a reasoned argument must be set out for all to see. Experiments must be reproducible.
The history of science is full of cases where previously accepted theories and hypotheses have been entirely overthrown, to be replaced by new ideas that more adequately explain the data. While there is an understandable psychological inertia—usually lasting about one generation—such revolutions in scientific thought are widely accepted as a necessary and desirable element of scientific progress. Indeed, the reasoned criticism of a prevailing belief is a service to the proponents of that belief; if they are incapable of defending it, they are well advised to abandon it. This self-questioning and error-correcting aspect of the scientific method is its most striking property, and sets it off from many other areas of human endeavor where credulity is the rule.

One of the reasons for its success is that science has a built-in, error-correcting machinery at its very heart. Some may consider this an overbroad characterization, but to me every time we exercise self-criticism, every time we test our ideas against the outside world, we are doing science. When we are self-indulgent and uncritical, when we confuse hopes and facts, we slide into pseudoscience and superstition.