The amount of knowledge which we can justify from evidence directly available to us can never be large. The overwhelming proportion of our factual beliefs continue therefore to be held at second hand through trusting others, and in the great majority of cases our trust is placed in the authority of comparatively few people of widely acknowledged standing.

We do not accept a religion because it offers us certain rewards. The only thing that a religion can offer us is to be just what it, in itself, is: a greater meaning in ourselves, in our lives, and in our grasp of the nature of things...a religion exists for us only if, like a piece of poetry, it carries us away. It is not in any sense a 'hypothesis.

But even physics cannot be defined from an atomic topography.

I shall suggest, on the contrary, that all communication relies, to a noticeable extent on evoking knowledge that we cannot tell, and that all our knowledge of mental processes, like feelings or conscious intellectual activities, is based on a knowledge which we cannot tell.

We could not, for example, arrive at a principle like that of entropy without introducing some additional principle, such as randomness, to this topography.

No inanimate object is ever fully determined by the laws of physics and chemistry.

Admittedly, scientific authority is not distributed evenly throughout the body of scientists; some distinguished members of the profession predominate over others of a more junior standing.