fully observe this distinction. Cases where voluntary or moral agency is concerned, can only be considered in physical inquiry so far as they properly come under the laws of inert matter, or belong to those kinds of physical action which are the subjects of dynamical or chemical research. To go beyond this is to confound physical causes with moral, physical science with metaphysical.

Observing this distinction, it would no doubt tend much to the promotion of accurate views if we could succeed in agreeing to disuse the term "cause" in one or other of these very distinct cases. But as custom has probably established the use of the term beyond the possibility of change, we must content ourselves by insisting strongly on the careful and constant adoption of some such distinctive appellations as those above suggested.

We have thus far merely contended that physical causes are such as are widely distinguished from moral; but we have not yet considered what their essential nature Is: to this we now proceed.

Nature of Physical Causes.

IN the study of physical causes there has been, doubtless, and still exists, a strong tendency to lose sight of the distinction just laid down; and from the familiar notion of moral causation, to imagine a similar sort of influence in the production of physical effects: to transfer the idea of voluntary power

as experienced in ourselves to mechanical agents; and by a creation of the fancy, by a sort of personification of the powers of nature, to invest physical, with the attributes of moral, action. But such indulgence of the imagination is here worse than idle; it has a direct tendency to confuse and entangle the chain of reasoning; and this consideration becomes of more importance in reference to the conclusions founded on physical inquiry. On all grounds, then, we ought surely to keep the search into physical truth as free as possible from such incongruous influence; and soberly investigate physical causes without being misled by the adoption of ideas so foreign to the subject.

Yet notions more or less allied to these have been prevalent among philosophers. This propensity for physical mysticism was pre-eminently fostered in the labyrinths of the scholastic and Cartesian systems of a past age. But the traces of it have not yet been wholly or effectually banished from our schools of science.

Even in later times many philosophers have sought to establish the notion of what they termed a" necessary connexion" or "efficient causation" in natural phenomena; an idea which nevertheless it would appear very difficult distinctly to explain.

It would seem as if they regarded material substances as possessed of some hidden virtues or properties, which confer on them the powers of physical agents; and imagined these occult qualities the

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secret soul which animates, as it were, the whole frame of nature.

In some instances, the adoption of these ideas may be traced to associations arising out of the common use of metaphorical language*. We talk of the chain of cause and effect; the links of that chain; the connexion of one event with another; the dependence of causes; the production of a result from its cause. These metaphors being taken from material objects, insensibly lead many minds to suppose some similar, real, and effective union between the events. But this is nothing more than the very common mistake of straining a metaphor beyond the points of parallelism, in which it properly applies, to others which are wholly incidental. Perhaps we might rather say these metaphors themselves have been adopted and conceived upon a false train of analogy. At any rate, if we retain the use of them, we should be careful not to be misled by the phraseology we employ into ideas at variance with the real nature of the relation intended to be expressed by it.

Another source, perhaps, from which these notions of "efficient causation" have derived strength, may be discovered in the vague conceptions which have sometimes prevailed with regard to the nature of mechanical forces. We might instance some speculations on the nature of " inertia," and the commu

* Idola fori.-Bacon.

nication of motion; as well as others connected with the questions once agitated respecting the "vis viva." Or, to take a more familiar example, the indistinct notions which frequently involve in a singular degree of mystery, the advantage obtained in the use of the mechanical powers. On witnessing the effects produced by these contrivances, the untaught mind can hardly help imagining a sort of creative energy which invests matter with new attributes, and supplies a source of active power capable of almost indefinite increase. Scientific investigation, indeed, dispels the illusion, yet it often continues to haunt both our language and our ideas relative to the nature of causation.

Opinions on the Nature of Causation.

WHETHER, however, originating in such misconceptions or not, whether pushed to a greater or less extent, some notions of this kind have prevailed very generally. But reasoners of an opposite school have arisen, who, aiming at a peculiar degree of precision and rigour in their speculations, have utterly denied and discarded all ideas of such active, efficient influence, which, they contend, is altogether chimerical; and have sought to reduce the whole nature and conception of cause and effect to the bare, naked, matter-of-fact, learnt from experience, that some one particular event or phenomenon in nature always invariably follows another in order of

time; the former being termed the effect, the latter the cause; that besides this mere invariable "sequence" (as it is termed), they have no other kind of connexion or dependence one on the other; all we know or can know of the matter is the simple fact, that such sequence does universally hold good; and that we cannot reverse the order. If we be prone to entertain the idea of any higher or more intimate connexion, this, they contend, is only a vague prepossession, utterly inadmissible in exact philosophic inquiry.

Against these views considerable objection has been raised; often, doubtless, from the abuse of them; because they were too exclusively dwelt upon, or pushed to unwarrantable extremes in their application.

But apart from these objections, the generality of inquirers seem to have felt unable to rest satisfied in a view of the subject apparently so little calculated to gratify the cravings of our intellectual curiosity, and seeming to conduct us to so little an extent into the secret workings of nature which we are so desirous to penetrate. They have generally yielded to the seemingly more natural but vague persuasion, that there is yet in the relation of cause and effect, some real, hidden, essential energy, which pervades and actuates all the operations of the material world.

And some, even of the most truly philosophic minds, have been unwilling wholly to acquiesce in