[T]he history of thought […] reveal[s] discrepancy between the intuitions of one age and those of a subsequent generation. But where the conflicting … - Henry Sidgwick

Many religious persons think that the highest reason for doing anything is that it is God’s Will: while to others ‘Self-realisation’ or ‘Self-development’, and to others, again, ‘Life according to nature’ appear the really ultimate ends. And it is not hard to understand why conceptions such as these are regarded as supplying deeper and more completely satisfying answers to the fundamental question of Ethics, than those before named: since they do not merely represent I what ought to be, as such; they represent it in an apparently simple relation to what actually is. God, Nature, Self, are the fundamental facts of existence; the knowledge of what will accomplish God’s Will, what is, ‘according to Nature’, what will realise the true Self in each of us, would seem to solve the deepest problems of Metaphysics as well as of Ethics. But […] [t]he introduction of these notions into Ethics is liable to bring with it a fundamental confusion between “what is” and “what ought to be”, destructive of all clearness in ethical reasoning: and if this confusion is avoided, the strictly ethical import of such notions, when made explicit, appears always to lead us to one or other of the methods previously distinguished.

Now, I agree with Mill in holding that the scientific study of the structures and functions of the different governments that have actually existed in human societies cannot well be pursued in complete separation from the scientific study of other important elements of the societies in question: whether the aim of the student is to ascertain the causes of the differences in such governments or to examine their effects. But I do not think that there is any fundamental difference, in this respect, between the study of political relations and the study of economic relations, or, again, of religion, of art, of science and philosophy, as factors of social life. In each of these eases the student concentrates his attention on one element of human history which can only be partially separated from other components of the whole complex fact of social development. Experience seems to show that this kind of concentration, and consequent partial separation of historical and sociological study into special branches, is unavoidable in the division of intellectual labour which the growth of our knowledge renders necessary in a continually increasing degree.

It is in their purely physical aspect, as complex processes of corporeal change, that [physical processes] are means to the maintenance of life: but so long as we confine our attention to their corporeal aspect,—regarding them merely as complex movements of certain particles of organised matter—it seems impossible to attribute to these movements, considered in themselves, either goodness or badness. I cannot conceive it to be an ultimate end of rational action to secure that these complex movements should be of one kind rather than another, or that they should be continued for a longer rather than a shorter period. In short, if a certain quality of human Life is that which is ultimately desirable, it must belong to human Life regarded on its psychical side, or, briefly, Consciousness.