It is extremely urgent to try and adapt our thoughts realistically to a world which has no fixed general direction either upward or downward, but is likely to vary largely according to what we do.

What great philosophers do for us is not to hand out such an all-purpose system. It is to light up and clarify some special aspect of life, to supply conceptual tools which will do a certain necessary kind of work. Wide though that area of work may be, it is never the whole, and all ideas lose their proper power when they are used out of their appropriate context. That is why one great philosopher does not necessarily displace another, why there is room for all of them and a great many more whom we do not have yet.

Few scientists would treat their cars as badly as they treat their conceptual schemes.

Morally as well as physically, there is only one world, and we all have to live in it

When some portion of the biosphere is rather unpopular with the human race-a crocodile, a dandelion, a stony valley, a snowstorm, an odd-shaped flint-there are three sorts of human being who are particularly likely still to see point in it and befriend it. They are poets, scientists and children. Inside each of us, I suggest, representatives of all these groups can be found.

None of us can study anything properly unless we do it with our whole being.

The world in which the kestrel moves, the world that it sees, is, and always will be, entirely beyond us. That there are such worlds all around us is an essential feature of our world.