There are four main departments of the spiritual life which aspire in this way to rise above the evils which beset our mortal state. They are Science and Art and Morality and Religion. As we know them in our experience, they are all of them due on the human side to a dissatisfaction with our experience as we find it. The scientific man is disturbed by the apparent chaos in his experience, and he sets out to give order to it, and he is satisfied in so far as he discovers that all the while it was not chaotic, as it seemed, but orderly. The artist is craving for a beauty which, in his ordinary experience, he does not find. He selects, he concentrates attention on certain aspects, to reach a satisfaction which the world otherwise seems not to give. The man of moral aspiration is dissatisfied with the world as he sees it, and he sets himself therefore to alter both himself and it, that it may be modelled more in accordance with the heart’s desire. And the religious man finds all of these sources of dissatisfaction working together within his soul; he seeks, and in faith finds, that which gives him both peace and power. Let us then begin with what is in itself the least rich of these forms of human activity, and consider how it is that Science reaches its unity. Let us first recall that there are two forms of multiplicity or division which we are seeking to overcome: that which arises from the clash of various ideals or desires, the antagonism of man with man; and that which arises from the changeableness of the world as we see it. With regard to the latter, science does indeed reach real unities; but they are unities which leave Time out of sight. Sometimes, no doubt, the subject matter which is handled is itself non-temporal, but not in the sense of being eternal. So, for example, geometry is entirely without relation to time. There is no temporal sequence between the equality of the sides and the equality of the angles in the isosceles triangle. But where the subject studied is something that changes in Time, it remains true that the aim of science is to reach an unchanging principle. So, for example, the student of biology may be trying to discover the unchanging principle which governs the successive variations of species. But when he has found it he has not really mastered the transitoriness; he has not in any way gathered up the past and dead into his present experience; he has merely found the principle which applies to every stage as that stage comes. He reaches some superiority to the transitoriness of things, only by abstracting from Time altogether.