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ascertain by the inductive canons). But when Mr. Mill asks for the cause, when a death takes place from eating unwholesome food, and decides that the cause is the whole assemblage of conditions of eating the food, combined with particular constitution, and state of the atmosphere, why does he not add the conditions of having bodily organs at all, of the existence of the food, &c., &c. ? These things are all connected through causation; but so many causes combine, that it would be useless to require the cause at such a distance from the effect; but this may be noted, that no one would ever call the existence of bodily organs the cause, simply because that has no tendency to produce the effect, though it is a necessary condition of it. Such cases are unfair, and only complicate the question ; that we do really reserve the word and the idea 'cause for active force, wherever that element can be detected and separated, is clear enough; the reason that in physical science this is so difficult to do, is, that all matter is probably resolvable into force, so that there is no phenomenon physically caused which is not the result of conflicting forces, and we can only select the one whose tendency is most obvious to produce the phenomenon; but there are some conditions absolutely passive, and yet absolutely necessary to physical phenomena, viz., the relations of space and time; and to these no one ever applies the word 'cause' without being immediately corrected by those who hear him. Thus if any one says, “ the cause of an eclipse is, that the moon is in the plane of the ecliptic,” every one feels that he should have said “ the condition;" it was a condition absolutely necessary, but utterly ineffective and passive, and is never considered a cause. Whereas if any one said that “ the cause of an eclipse is the shadow thrown by the earth," or 'the opacity of the earth,' that, being regarded as the really active element in resisting in some way the passage of light, no one feels the incorrectness of the phrase ; and yet the passive condition is quite as necessary to the event as the active obstruction. So, too, every one would feel Mr. Mill's example, that “the cause of a surprise was the sentinel's being off his post," as incorrect; the allurement or force which drew him off his post, might be so called, because in doing so it removed a resisting power which would have prevented the surprise : but by common

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consent 'cause' is always reserved for the active element, or the prominently active element, in producing an effect; and in matters of personal causation, mental or physical, where the consciousness of effort comes home, no one ever misapplies the term to the passive conditions; no one calls the cause of a leap the muscles or sinews of the body, though they are necessary conditions ; nor the cause of a self-sacrifice, the knowledge which was necessary to it; nor the cause of writing a book, that a man has time for it (which is a necessary condition); there is quite enough consent amongst men in their employment of the term, to prove that it does denote a distinct element, the active element in the production of phenomena ; and its misapplication in physical nature is easily accounted for by the impossibility of being able to perceive or understand the active element in processes quite external to our own consciousness.

But we must hasten to draw this prolix discussion to an end. Differing thus entirely with Mr. Mill as to the rationale of the inductive process, the grounds of inductive inference, and the facts of consciousness which we express by expectation, or probability, we agree entirely with him (if he really intends that this is the basis of his whole work) that the ascertainment of a cause (in the sense of the whole assemblage of active and passive conditions) is grounded entirely on probability, because the assumption that there will always be invariable phenomenal antecedents at all, is one of no necessary kind.* True, we believe that probability itself rests in our minds on the faith in efficient causes, and is only the state of mind in which we perceive the traces of causes more or less frequent in their operation ; but the induction of phenomenal causes rests entirely on the grounds of probability, joined with the natural presumption (valid till anything is proved to the contrary) that these are themselves the real efficient energies.

Once having passed the establishment of the fundamental

Assuming the doetrine of efficient causes, we might easily calculate the probability for uniform physical antecedents from the observed uniformity now established: but without this assumption this is impossible, as the calculation itself involves the principle that the same causes produce the same effects.

principle of Induction, the theory becomes simple enough, and the practical applications only are difficult. All the rest of the process consists in observing or obtaining the causes supposed to be possible, and excluding (as at least not complete causes, in the larger sense) those which are not followed by the phenomenon, and retaining (as at least necessary conditions) those whose removal is followed immediately by the disappearance of the phenomenon; and when these methods will not apply, success may be obtained by observing the changes in antecedents which accompany the changes in consequents (on the principle that an effect cannot vary without a variation in its cause, so that anything which remains entirely unchanged while the phenomenon varies cannot be its whole cause, at least), or by removing known causes, and then effects, in order to reach more clearly the unknown residual cause. The theory of this part of the subject is stated clearly; and even if not systematized into the most symmetrical form, yet it is given much more systematically by Mr. Mill than had been previously done. The method of residues might perhaps have been left to enumerations of practically useful rules, like those of Dr. Whewell; there is nothing peculiar to it depending on the theoretical definition of cause, and it may be classed among the contrivances for simplifying and resolving the phenomena to be observed. Dr. Whewell criticizes Mr. Mill's examples with much severity, and probably not without some reason: but this does not affect the theory, which is independent of such examples, being the true rationale of operations which Dr. Whewell and every one else performs every day in judging of the matters of common life.

We must notice one point more before we conclude. Dr. Whewell and Mr. Mill are at variance as to the function of Deduction in the future history of physical science, but they both agree to maintain that deduction alone is likely to effect much in the further progress of the moral sciences, on the ground that we have arrived already at the highest generalizations of these sciences. We confess that we look on such an opinion with extreme astonishment. In political economy indeed, this is certainly true; but in psychology, ethics, and religious philosophy, we confess that we should scarcely expect such an opinion, from any thinker, except one who believed in the omnipotence of the laws of association, the results of Scotch analysis, or the philosophy of a Bridgewater treatise. The great failure of these sciences has been mainly owing to the difficulty of seizing fast the living phenomena of mind before they vanish, leaving only faint heavy traces on the memory ; this recommendation encourages the disposition to avoid this difficulty by accepting the old rough generalizations, which would only represent the shadows of mental phenomena, and using them to deduce tight sharp systems, which (like that of the late Mr. Mill) manage to explain a small portion of our experience, by declining to believe in the greater part of it altogether. In the physical sciences it is the ascertainment of the probable cause which is difficult; the process of verification by comparison with the results of empirical laws is easy and definite: we know clearly what facts ought to be deduced, and how far they do correspond with the results of theory. The difference in the case of the mental and moral sciences is one worthy of note, and suggests we believe the true solution of Dr. Whewell's difficulty (so strangely solved in his book by quietly re-stating it in another shape) as to why the Greeks failed so entirely in physical science. That it was not anything inherent in the inductive process is evident enough; they reasoned with all the practical skill of a cultivated nation, and all practical inference involves the inductive process. Besides, as Dr. Whewell says, they observed facts accurately, and classed them with judgment : and Plato's inductions as to the meanings of words are excellent specimens of the most perfect inductions. But their stumbling-block was one as to the nature of the evidence they had to expect for their conviction. Accustomed to the inductions of mental science,—where no cause could even be suggested that did not contain something capable of deduction into a very similar effect, where the probability of a suggestion was seen even before it could be thrown out at all, and the mind knew before it began its search what kind of cause it must look for,—they looked out for the same kind of evidence for a physical cause before they even thought of trying it, and expected to find some evidence in a mental comparison, although neither the operation of the cause nor the nature of the effect were acces

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sible to their consciousness : they had not seized the idea that they must not expect to understand the processes of outward causes, but only to know their results; and consequently the whole physical philosophy of the Greeks was an attempt to identify mentally the effect with its cause, to feel often some not only necessary but natural connection, where they meant by natural, that which would, per se, carry some presumption to their own mind, as the suggestion of mental causes for mental effects were accustomed to do. They wanted to see some reason why the physical antecedent should produce this particular consequent, and their only attempts were in directions where they could find such reasons. Thus all the Greek physical philosophy began by assuming that all changes were only alterations of form, not of substance, and attempting to indicate them by something which professed to detect the same elements in different disguises, or the same atoms in different local positions. They could not enter into the mode of real change, and so they disbelieved it; their theories, such as they are, all strive to render obvious at once to the mind the kind of connection between cause and effect. The Pythagoreans detected mathematical analogies ; Plato, mathematical and moral; the Ionians one single, all-pervading, physical principle; and others the local changes of eternal atoms; and even Aristotle gropes after phrases for physical facts (as 'natural and 'violent,' &c.), which may help to convey a kind of factitious mental authority, from their associations with mental experience. It was the necessary absence of this kind of evidence in physical inquiries, we think, which so long shut out the Greeks from our physical knowledge; and it is perhaps the presence of this kind of evidence in mental inquiries, that keeps our moral sciences so backward, while the physical have gained so much. Accustomed to find verification easy and safe for physical inductions, and the induction of causes difficult, we are at once misled by the prima facie plausibility of the inductions of mental science, and by the apparent agreements of deduction with empirical law; quite forgetting that a much more stringent compa

a rison is needed in mental phenomena to identify a result of theory with a fact of consciousness than is requisite in physical science. In truth, the question of resemblance

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