portion of M tends to keep a definite ratio to M', when the thing to be proved is that the _whole_ of M tends to keep a definite ratio to M'? Fisher's argument is a clear _non-sequitur_. If it proves anything, it proves that a sum of money,[163] not part of M, and another sum of money, an unknown fraction of M, each independently, for reasons peculiar to each sum, tends to keep a constant ratio to M'. This gives us _l'embarras des richesses_ from the standpoint of a theory of causation! Two independent factors, bank-reserves and money in the hands of depositors, each tending to hold bank-deposits in a fixed ratio, and yet each moved by independent causes! By what happy coincidence will these two tendencies work together? Or what is the causal relation between them? And if, for some yet to be discovered reason, Professor Fisher should prove to be right, and there should be a fixed ratio between M as a whole and bank-deposits, would it not indeed be a miracle if all three "fixed ratios" kept together? Bank-deposits, indissolubly wedded to three independent variables[164] (independent, at least, so far as anything Professor Fisher has said would show, and independent in large degree, certainly, so far as any reason the present writer can discover), must find their treble life extremely perplexing. May it not be that Professor Fisher has pointed the way to the real fact, namely, that bank-deposits are subjected to a multitude of influences, no one of which is dominant, which prevent any fixed ratio between bank-deposits and any other one thing? At a later point, I shall maintain that this is, indeed, the case.