quite peculiar. Physical forces subject to causation are capable indeed of many combinations, but they return readily in a simple way to their first terms. In life the first term is often entirely lost in evolution, and the several stages and terms can be approached no otherwise than through the laws of variation and inheritance which first produced them, if indeed they can be reached at all. These laws are laws quite peculiar to living things, and receive no sufficient explanation under causal dependencies. We cannot divide and compound plastic powers, nor express their action by additions and subtractions, as if they were a simple congeries of physical forces. The facts are peculiar and the laws are peculiar. No definable causes cover them. The belief that they do is not an induction, it simply the momentum of an induction in one field expended in another field.

We might indeed be tempted to attribute this difficulty in the comprehension of life under the laws of causation to the obscurity of the terms, did not the problem assume a new and more pronounced form when we pass on to consciousness, and so up to mental processes. By the growth of the new tendencies, we see at once that we are not merely on the bounds of the old kingdom, but have entered within the limits of a new one.

§ 4. It is impossible to tell how low down in animal life the simplest facts of consciousness arise. We are more likely to refer them to an origin too early than one too late, since the external appearance of actions ordered instinctively are quite the