Science, by itself, cannot supply us with an ethic. It can show us how to achieve a given end, and it may show us that some ends cannot be achieved.

War can only be abolished by the establishment of a world government.

The most savage controversies are about matters as to which there is no good evidence either way.

Do not use power to suppress opinions you think pernicious, for if you do the opinions will suppress you.

Do not feel certain of anything.

In the higher walks of politics the same sort of thing occurs. The statesman who has gradually concentrated all power within himself ... may have had anything but a public motive... The phrases which are customary on the platform and in the Party Press have gradually come to him to seem to express truths, and he mistakes the rhetoric of partisanship for a genuine analysis of motives... He retires from the world after the world has retired from him.

We may define "faith" as the firm belief in something for which there is no evidence. Where there is evidence, no one speaks of "faith." We do not speak of faith that two and two are four or that the earth is round. We only speak of faith when we wish to substitute emotion for evidence. The substitution of emotion for evidence is apt to lead to strife, since different groups, substitute different emotions.