How we learn to

and mental

as cases of

the same

law.

writing, are caused by our voluntary determinations, is that we always find that the voluntary determinations are followed by the motions. But if any one were to tell me that hearing good news is not the cause of joy, or that my reading a sound demonstration is not the cause of my assenting to it, this would contradict a fact of direct cognition, just as much as if he were to assure me that sugar was bitter or toothache pleasant.

We say that fire causes heat, and that good news causes identify joy. Fire causing heat is a fact of matter; and this relaphysical tion of cause and effect is not within our consciousness, causation but is, as I believe, inferred by us from the facts. Good news causing joy is a fact of mind; and this relation of cause and effect is within our consciousness, and is, I think, self-evidently no mere inference, but a fact of direct cognition. But mankind naturally and spontaneously regard these as both alike cases of causation; and I believe that here, as in so many other cases, the spontaneous belief of mankind is right. But how do we come mentally thus to ascribe the same law of causation to these two sets of actions, the physical and the mental, between which there is so little intelligible resemblance? I think, though the subject is most difficult to analyse, that the connecting link by which we learn to identify causation as cognised within the mind with causation as inferred in the world of matter outside of it, consists in the fact that we have the power, inexplicable as that power is, of making our own will an acting cause in the world of matter. Thus, if I will to think, my thoughts act as desired; if I will to write, my fingers and my pen act as desired; and though the causal connexion, as already pointed out, is within the sphere of consciousness in the one case and not in the other, yet the effect follows the cause in both cases with equal certainty, and we learn to identify the nature of the causal action in the two cases. In a word, we identify the two facts of mental causation and physical causation in consequence of the fact that a mental determination is capable of becoming a physical cause; as when the determination of my will causes the

case of a

but no

motion of my pen. If a being were to exist, having powers Imaginary of perception and thought like our own, but without any being with power whatever of acting on the world around it, I think thought it is certain that its ideas of causation would be very unlike motor ours. It would have exactly the same idea of causation powers. that we have, in the sense in which causation is resolvable into mere "invariable and unconditional sequence;" but it would have no idea of causation in the sense of force; and force, as it appears to me, is the essential thing in our idea of causation.

uni

agree with Mill, and

differ.

It will be seen that in this account of our original cognition of the relation of cause and effect, I ascribe it to experience, although I differ from Mill and the rest of Where I those who regard causation as nothing more than form and unconditional sequence." I agree with them in where I ascribing it to experience; but they ascribe it to experience of the facts of the external world which we observe; I ascribe it to experience of the facts of the mind, of which we are directly cognizant. When we say, for instance, that "fire is the cause of heat," we state a fact which we have learned purely from external observation. But Mr. Mill maintains that when we say that "fire is the cause of heat," our only meaning is, that "fire always emits heat, and nothing more than the fire itself is needed in order to have heat." I think, on the contrary, that more is meant than this. I think we apply the analogy of our own mental experience to the external world, and infer that fire causes heat in the same sense in which good news causes joy, or evidence causes belief. It may be said this analogy is plausible only to that intellectual state in which men try to explain the facts of the external world by the fancies of their own minds. I think, on the contrary, that the rejection of this analogy belongs to that exploded system of psychology in which mind and matter were regarded as distinct and totally unlike substances. The progress of science has gradually brought us back to the spontaneous conclusion of the earliest conscious thought, before metaphysics were invented; namely, that the mind of man is not distinct from the material world in the

Summary.

Belief in

the infinity of space and

time.

midst of which it is placed, but is the highest product of the forces of that world; and what we have discovered concerning the dynamics, both of inorganic matter and of life, makes it highly probable, if not indeed quite certain, that in every physical and every mental change there is some transformation of energy.

To sum up in the fewest words possible the results of this chapter:-Time, space, and causation are facts of the universe which have become forms of thought in consequence of coming within the sphere of our consciousness. Our conceptions of time, space, and causation are results of the experience of the race which have become forms of thought for the individual.

But though I believe this account of the matter to be true so far as it goes, I do not think it exhausts the question. Any account of our conceptions of time and space, if complete, ought to explain why we believe in the infinity of both. Those who regard these conceptions as mere results of experience, say that we have never found any limit to space, and are therefore unable to conceive of any; and that we have never found an end of time, and are therefore unable to conceive of any. I cannot, however, think this satisfactory. We believe that time is alike without end and without beginning; and any theory of the subject ought to account for this twofold belief. Now the pure and simple experience-theory does not account for this. It accounts for the belief that time is without an end, by the fact that we have never had experience of any portion of time without another portion of time Difference coming after it. But this will not apply to our belief that time is without a beginning; for the first time that any one's consciousness was awakened, he had at that moment past, and experience of a portion of time without having experience of any other portion of time coming before it; so that, for anything that mere experience can witness to, there is nothing inconceivable in a beginning of time.1 I think

between

our belief of an eternal

of an

eternal

future.

1 This difference has been pointed out to me in conversation by my friend the Rev. Dr. Reichel, Vicar of Mullingar.

this is conclusive proof that, although we obtain our first knowledge of time by direct cognition, and it has become a form of our thought by hereditary habit, yet there is something in our knowledge of its properties for which mere habit will not account, and which can be referred only to that mental intelligence which is not a result of habit. If this is true of the conception of time, it is no doubt equally true of the conceptions of space and of causation.

This mental intelligence is to form the subject of the next chapter.

NOTE.

THE PHILOSOPHY OF KANT.

system

Reason" is

with

I SHALL probably be told that I have misunderstood Kant's philosophy; and I admit that, like most of those who write about him, I have not any knowledge of his works at first hand. But I believe I am right. The system unfolded in his "Critique The of the Pure Reason" is one of absolute idealism, deriving all the of Kant's principles of knowledge from the constitution of the mind: this "Pure is, and Kant perceived it to be, logically identical with pure idealism, scepticism, or that system which denies the possibility of our identical really knowing anything except that which passes within the mind. It is true that, in his " Critique of Practical Reason," he arrived at a different conclusion, and showed how faith was pos- "Practical sible. But I believe I am right in saying that his "Pure Reason" Reason" is in no way a basis for his "Practical Reason;" that, on the contrary, his "Practical Reason," though of course it speaks in a philosophical language, is in reality nothing else than faith, building itself up in spite of the sceptical conclusions of the pure reason, or faculty of speculative philosophy.

scepticism:

that of his

is faith.

CHAPTER XXXIX.

The most

gence is a primary fact.

I have

affirmative

now to

argue it

IN

MENTAL INTELLIGENCE.

N my opinion, the most important question now under important discussion in the sciences of life and mind, and I question of biology is think I may add the most important question that ever whether intellican be debated in those sciences, is this:-Is intelligence an ultimate primary fact, without physical cause, and without any cause except Creative Power; or only a resultant, put together out of unintelligent elements by the action of the laws of habit? In the chapter on Natural Selection I have argued, in opposition to the theories of Darwin argued the and H. Spencer, that the organizing intelligence which of organ adapts one part of the organism to another is an ultimate izing intelligence, fact, not to be accounted for, as those most able writers and have endeavour to account for it, by the principles of habitual self-adaptation and natural selection. In this chapter I shall have to argue the same of mental intelligence,-namely, that it is an ultimate fact, not to be accounted for by the laws of habitual association. In the chapter on Intelligence,1 I have given my reasons for believing that organizing intelligence and mental intelligence are only different manifestations of one principle. Possibly, not many of my readers will agree with me in this; but it is most probable that all who think with me as to the primary and independent nature of intelligence in either of these two cases will agree with me in the other case also. It is, however, necessary to argue the question of the nature of organizing intelligence, and of mental intelligence, on totally different grounds. The argument as to the latter is, at least to me, the most difficult; but this is not because I think it less

of mental.

Difficulty of the

1 Chapter XXVII.