1. The Unknowable is the cause of all the phenomena we observe.
2. The constitution of gunpowder is the cause of its explosiveness.[48]
3. The fall of a spark was the cause of the actual explosion of the powder.[49]
Or these:
1. Life is the cause of all vital manifestations.
2. The inherited nature of a hen's egg is the cause of its producing a chick and not a duckling.
3. The cause of the development of the chick embryo is the warmth supplied by the incubating mother.[50]
In each case the reference under (1) is to a transcendent cause which produces the phenomena under consideration. I suggest that the word Source should here be used instead of cause. In each case the reference under (2) is to the nature or constitution of that within which some process occurs. I suggest that the word ground should here be used instead of cause. In each case the reference under (3) is to some external influence. I suggest that the word condition should here be used instead of cause. We thus eliminate the word cause altogether. But since, in nine cases out of ten, the conditions, or some salient condition, is what is meant by cause in popular speech, and in the less exact sciences, the word cause may perhaps be there retained with this particular meaning. These are of course merely suggestions towards the avoidance of puzzling ambiguity. One could wish that Spencer could have thought out some such distinctions to help his sorely perplexed readers.
One could wish, too, that he had devoted his great powers of thought to a searching discussion of the different types of relatedness which are found in nature, and to a fuller consideration of a synthetic scheme of their inter-relatedness. It is imperative that our thought of relations should have a concrete backing. 'Every act of knowing', says Spencer, 'is the formation of a relation in consciousness answering to a relation in the environment.' But the knowledge-relations are of so very special a type; and the relations in the environment are so many and varied. Much more analysis of natural relations is required than Spencer provides. I do not mean, of course, that there is any lack of analysis—and of very penetrating analysis—in the Psychology, the Biology, the Sociology, and the Ethics. I mean that in First Principles, which must be regarded as his general survey of the philosophy of science, there is no searching analysis of the salient types of relationship which enter into the texture of this very complex world. Such omnibus words as differentiation, integration, segregation, do duty in various connexions with convenient elasticity of meaning to suit the occasion. But apart from qualifying adjectives,[51] such as astronomic, geologic, and so on up to artistic and literary, there is too little attempt at either a distinguishing of the types of relatedness or at a relationing of the relations so distinguished. One just jumps from one to another after a break in the text, and finds oneself in a wholly new field of inquiry. Little but the omnibus terminology remains the same. Nor does the Essay on the Classification of the Sciences, with all its tabulation, furnish what is really required. What one seeks to know is how those specific kinds of relatedness which characterize the successive phases of evolutionary progress, inorganic, organic, and superorganic, differ from one another and how they are connected. This one does not find. The impression one gets, here and elsewhere, is that all forms of relatedness must somehow, by the omission of all other specific characters, be reduced to the mechanical type. This, no doubt, is unification of a sort. But is it the sort of unification with which a philosophy of science should rest content?
It may be said that unification can only be reached by digging down to some ubiquitous type of relation which is common to all processes throughout the universe at any stage of evolution. But what, on these terms, becomes of evolution itself as a problem to be solved? Surely any solution of that problem must render an account of just those specific modes of relatedness which have been ignored in digging down to the foundations. Surely there must be unification of the superstructure as well as of the substructure. Here and now is our world, within the texture of which things stand to each other in such varied relations, though they may be reducible to a few main types. There, in the faraway part, was the primitive fire-mist, dear to Spencer's imagination, in which the modes of relationship were so few and so simple, and all seemingly of one main type. How do we get in scientific interpretation from the one to the other? Will it suffice to breathe over the scene the magic words differentiation and integration? Spencer appears to think so. Of course he did exceptionally fine work in elucidating the modes of differentiation and integration within certain relational fields—though he sometimes uses the latter word for mere shrinkage in size.[52] But what one asks, and asks of him in vain, is just how, within a connected scheme, the several relational fields in the domain of nature are themselves related, and how they were themselves differentiated. How, for instance, did the specific relationships exhibited in the fabric of crystals arise out of the primitive fire-mist relations? At some stage of evolution this specific form of relatedness came into being, whereas before that stage was reached it was not in being. No doubt we may say that the properties of the pre-existing molecules were such that these molecules could in due course become thus related, and enter into the latticed architecture of the crystal. They already possessed the potentiality of so doing. And if we have resort to potentialities, all subsequently developed types and modes of relatedness were potentially in existence ab initio—they were, as Tyndall said, 'once latent in a fiery cloud.' But it is difficult to see how the specific modes of relatedness which obtain within the crystal, can be said to exist prior to the existence of the crystal within which they so obtain.