Theory and experiment alike become meaningless unless the scientist brings to them, and his fellows can assume in him, the respect of a lucid honesty with himself. The mathematician and philosopher W. K. Clifford said this forcibly at the end of his short life, nearly a hundred years ago.
If I steal money from any person, there may be no harm done by the mere transfer of possession; he may not feel the loss, or it may even prevent him from using the money badly. But I cannot help doing this great wrong towards Man, that I make myself dishonest. What hurts society is not that it should lose its property, but that it should become a den of thieves; for then it must cease to be a society. This is why we ought not to do evil that good may come; for at any rate this great evil has come, that we have done evil and are made wicked thereby.
This is the scientist’s moral: that there is no distinction between ends and means. Clifford goes on to put this in terms of the scientist’s practice:
In like manner, if I let myself believe anything on insufficient evidence, there may be no great harm done by the mere belief; it may be true after all, or I may never have occasion to exhibit it in outward acts. But I cannot help doing this great wrong towards Man, that I make myself credulous. The danger to society is not merely that it should believe wrong things, though that is great enough; but that it should become credulous.
And the passion in Clifford’s tone shows that to him the word credulous had the same emotional force as ‘a den of thieves’.
The fulcrum of Clifford’s ethic here, and mine, is the phrase ‘it may be true after all’. Others may allow this to justify their conduct; the practice of science wholly rejects it. It does not admit the word “true” can have this meaning. The test of truth is the known factual evidence, and no glib expediency nor reason of state can justify the smallest self-deception in that. Our work is of a piece, in the large and in the detail; so that if we silence one scruple about our means, we infect ourselves and our ends together. [74-5]