under which a perpetual motion, that is, a perpetual source of self-created energy might exist. The larger part of the philosophic world has long held that in mental acts there is free will-in short, self-causation. It is in vain to attempt to reconcile this doctrine with that of an intuitive belief in causation, as Sir W. Hamilton candidly allowed.

It is quite obvious, moreover, that to assert the existence of a cause for every event, cannot do more than remove into the indefinite past the inconceivable fact and mystery of creation. At any given moment matter and energy were equal to what they are at present, or they were not; if equal, we may make the same inquiry concerning any other moment, however long prior, and we are thus obliged to accept one horn of the dilemma-existence from infinity, or creation at some moment. This is but one of the many cases in which we are compelled to believe in one or other of two alternatives, both inconceivable. My present purpose, however, is to point out that we must not confuse this supremely difficult question with that into which inductive science inquires on the foundation of facts. By induction we gain no certain knowledge; but by observation, and the inverse use of deductive reasoning, we estimate the probability that an event which has occurred was preceded by conditions of specified character, or that such conditions will be followed by the event.

Definition of the Term Cause.

Clear definitions of the word cause have been given by several philosophers. Hobbes has said, 'A cause is the sum or aggregate of all such accidents both in the agents

d Cambridge Philosophical Transactions,' [1830] vol. iii. pp. 369372.

S

; or

and the patients, as concur in the producing of the effect propounded; all which existing together, it cannot be understood but that the effect existeth with them; that it can possibly exist if any of them be absent.' Dr. Brown, in his 'Essay on Causation,' gave a nearly corresponding statement. A cause,' he says, 'may be defined to be the object or event which immediately precedes any change, and which existing again in similar circumstances will be always immediately followed by a similar change.' Of the kindred word power, he likewise says:f Power is nothing more than that invariableness of antecedence which is implied in the belief of causation.'

These definitions may be accepted with the qualification that our knowledge of causes in such a sense can be probable only. The work of science consists in ascertaining the combinations in which phenomena present themselves. Concerning every event we shall have to determine its probable conditions, or group of antecedents from which it probably follows. An antecedent is anything which exists prior to an event; a consequent is anything which exists subsequently to an antecedent. It will not usually happen that there is any probable connection between an antecedent and consequent. Thus nitrogen is an antecedent to the lighting of a common fire; but it is so far from being a cause of the lighting, that it renders the combustion less active. Daylight is an antecedent to all fires lighted during the day, but it probably has no appreciable effect one way or the other. But in the case of any given event it is usually possible to discover a certain number of antecedents which

e 'Observations on the Nature and Tendency of the Doctrine of Mr. Hume, concerning the Relation of Cause and Effect.' Second ed. P. 44. f Ibid. p. 97.

seem to be always present, and with more or less probability we conclude that when they exist the event will follow.

occur.

Let it be observed that the utmost latitude is at present enjoyed in the use of the term cause. Not only may a cause be an existent thing endowed with powers, as oxygen is the cause of combustion, gunpowder the cause of explosion, but the very absence or removal of a thing may also be a cause. It is quite correct to speak of the dryness of the Egyptian atmosphere, or the absence of moisture, as being the cause of the preservation of mummies, and other remains of antiquity. The cause of a mountain elevation, Ingleborough for instance, is the excavation of the surrounding valleys by denudation. It is not so usual to speak of the existence of a thing at one moment as the cause of its existence at the next, but to me it seems the commonest case of causation which can The cause of motion of a billiard ball may be the stroke of another ball; and recent philosophy leads us to look upon all motions and changes, as but so many manifestations of prior existing energy. In all probability there is no creation of energy and no destruction, so that as regards both mechanical and molecular changes, the cause is really the manifestation of existing energy. In the same way I see not why the prior existence of matter is not also a cause as regards its subsequent existence. All science tends to show us that the existence of the universe in a particular state at one moment, is the condition of its existence at the next moment, in an apparently different state. When we analyse the meaning which we can attribute to the word cause, it amounts to the existence of suitable portions of matter endowed with suitable quantities of energy. If we may accept Horne Tooke's assertion, cause has etymologically the meaning of thing before. Though, indeed, the origin of the word is very obscure, its

vacate e rac Tors, then, 3 singled from the moup of positive poppannad os vilt with more or less probability, In this sense, there is to particular Bogor bp Aron, ktowedge of cases and our general kordgs & te qmitations, or succession of combinatione, en we pretratata of nature are presented tor, of fond M. in experimental inquiry.

Distinction of Inductice and Deductive Results.

prox

We must care wold confusing together inductive investigations whion terminate in the establishment of general laws, and those which seem to lead directly to the knowledge of future particular events. That process only can be called induction which gives general laws, and it is by the subsequent employment of deduction that we can alone anticipate particular events. If the observation of a number of cases shews that alloys of metals

h Leslie, Inquiry into the Nature of Heat,' Note xvi. p. 521.

fuse at lower temperatures than their constituent metals, I may with more or less probability draw a general inference to that effect, and may thence deductively ascertain the probability that the next alloy examined will fuse at a lower temperature than its constituents. It has been asserted, indeed, by Mr. J. S. Milli, and partially admitted by Mr. Fowlerk, that we can argue directly from case to case, so that what is true of some alloys will be true of the next. Doubtless, this is the usual result of our reasoning, regard being had to degrees of probability; but these logicians fail entirely to give any explanation of the process by which we get from case to case. To point, as Mr. Mill has done, to the reasoning, if such it can be called, of brute animals, is little better than to parody philosophy. It may well be allowed, indeed, that the knowledge of future particular events is one main purpose of our investigations, and if there were any process of thought by which we could pass directly from event to event without ascending into general truths, this method would be sufficient, and certainly the most brief and simple. It is true, also, that the laws, of mental association lead the mind always to expect the like again in apparently like circumstances, and even animals of very low intelligence must have some trace of such powers of association, serving to guide them more or less correctly, in the absence of true reasoning faculties. But it is the very purpose of logic, according to Mr. Mill, to ascertain whether inferences have been correctly drawn, rather than to discover themm. Even if we can, then, by habit,

i 'System of Logic,' bk. II. chap. iii. Mr. Bain has not adopted the views of Mr. Mill, on this particular point, so far as I can ascertain. See his Inductive Logic,' p. 1.