They make poor observations, because they choose among the results of their experiments only what suits their object, neglecting whatever is unrelated to it and carefully setting aside everything which might tend toward the idea they wish to combat.

Science repulses the indefinite.

When we meet a fact which contradicts a prevailing theory, we must accept the fact and abandon the theory, even when the theory is supported by great names and…

The science of life is a superb and dazzlingly lighted hall which may be reached only by passing through a long and ghastly kitchen.