It must be remembered that A, B, C stand for _relationships_ and that the related things are progressively more complex within more complex relational wholes. Relationships are every whit as real as are the terms they hold in their grasp. I do not say more real; but I say emphatically as real. And if this be so, then they ought somehow to be introduced into our formulae, instead of being taken for granted. We give H{2}O as the formula for a molecule of water. But that molecule is something very much more than two atoms of hydrogen + one atom of oxygen. The absolutely distinctive feature of the molecule is the specific relatedness of these atoms. This constitutive mode of relatedness is, however, just taken for granted. And it is scarcely matter for surprise that, when we find not less specific modes of vital relatedness in the living organism, they are too apt to be just ignored! Revert now to the empirical outcome of scientific research, for as such I regard it, that new constitutive properties emerge when new modes and types of relatedness occur, and when new products are successively formed in evolutional synthesis. This, it will be said, involves the acceptance of what is now commonly called creative evolution. I am far from denying that, in the universe of discourse where Source is under consideration, the adjective is justifiable. But, in the universe of discourse of science, I regard it as inappropriate. What we have is just plain evolution; and we must simply accept the truth--if, as I conceive, it be a truth--that in all true evolution there is more in the conclusion than is given in the premises; which is only a logical way of saying that there is more in the world to-day than there was in the primitive fire-mist. Not more 'matter and energy', but more varied relationships and new properties, quite unpredictable from what one may perhaps speak of as the fire-mist's point of view. This is no new doctrine, though it has received of late a new emphasis. Mill, dealing with causation,[55] speaks of a 'radical and important distinction'. There are, he says in substance, some cases in which the joint effect of the several causes is the algebraical sum of their separate effects. He speaks of this as the 'composition of causes', and illustrates it from the 'composition of forces' in dynamics. 'But in the other description of cases', he says, 'the agencies which are brought together cease entirely, and a totally different set of phenomena arise.' In these cases 'a concurrence of causes takes place which calls into action new laws bearing no analogy to any that we can trace in the separate operation of the causes'. They might, he suggests, be termed 'heteropathic laws'. G. H. Lewes, too,[56] in his _Problems of Life and Mind_, drew the distinction between properties which are _resultant_ and those which are _emergent_. These suggestions were open to Spencer's consideration long before the last edition of _First Principles_ appeared.