no real or substantial indications of design can be rationally admitted. And those who are bent on finding such evidences everywhere, are too apt hastily to decide that one result was actually ordained with a special view to another, where the connexion is too remote to allow us reasonably to consider it so. Such a course is apt to produce no other result than that of exposing to reproach the whole investigation of final causes.

And the judicious inquirer will per

ceive at once the injury done to the truth by weak and delusive arguments adduced in its support, and how little need there is for such doubtful aid in the abundance of substantial evidences with which we are surrounded.

Use of Final Causes in Science.

THE only case in which there can be any reasonable ground for dispute about the use of terms, is where they may be so chosen as to lead to ambiguity or mistake, as to the ideas for which they stand.

Now much discussion has arisen as to the investigation of final causes; and, especially, whether the study of them be a legitimate part of the province of natural philosophy. But all dispute may, I conceive, be avoided, simply by attention to the precise meaning of the term.

According to what was above observed, we certainly may agree to use the term "final cause" as simply equivalent to describing the fact of the

adjustment which we actually observe. Our meaning will then be totally free from all ambiguity. But then, this is only an inconvenient and circuitous way of expressing what would be more clearly and simply described by the plainer terms, "fitness," "arrangement," "adaptation," of things to each other.

On these grounds I agree, therefore, with those who prefer to discard altogether the use of the term "final cause," and to employ in its stead only the plain terms "adjustment," &c., which express the facts we actually observe or inductively collect.

We should thus be relieved from all controversy about the introduction of final causes in natural philosophy. Since no dispute exists as to the propriety, nay necessity, of considering those adaptations and arrangements in our physical inquiries which are in a great measure forced on our observation, and without which our researches would be miserably defective in their most valuable, instructive, and important results.

In regard to the reasoning, we should thus escape all danger of perplexing (even in appearance) the order and chain of it; which is often greatly entangled by the mere introduction of an ambiguous term. By adhering to these more simple and perspicuous modes of expression, we should more palpably preserve that distinctness of meaning in form, which, at all events, must be preserved in substance. We shall keep clear the inferences from the order of physical causes, and the study of the

causes themselves: in other words, we shall not confound physical causes with moral agency; but shall be prepared, in the only sound and legitimate way, to deduce the indications of the latter from the former.

The term "final cause," employed in the sense at first explained, as that which it must in strictness bear; viz., as involving a reference to the processes of creative intelligence; is doubtless most improperly introduced into the investigation by which we advance to the elementary truths of natural philosophy. And manifestly for this reason, that it expresses, and thus misleads us into making the assumption of the very thing which it ought to be our object to prove from the truths elicited by natural science; viz., the existence of creative intelligence, of an omnipotent and omniscient Creator.

But it has been contended that the study of "final causes" may be, and has been, of important use in physical discovery: and the well-known example is adduced of the discovery of the circulation of the blood by Harvey, in consequence of a reflection into which he was led on the probable use of the valves in the veins.

Let us keep to unambiguous terms, and the case merely shows that a good conjecture, derived from the observed fitness of the valves for such an office as would be discharged by them, if the circulation were a fact, led him to the right train of analogy, which he so completely verified by observation. In this way

it is often the case in the researches of the naturalist, that from observing the obvious purpose of some one organ, he is able to conjecture the probable use of some other, which, but for such analogy, would be totally obscure; and such conjectures, if well founded, seldom fail to be borne out by actual experimental proof.

The uses of things (simply so considered,) wherever they have been fairly traced and established, supply a perfectly just, and most useful ground of analogy for guiding us to inductive conclusions. The habit of observing such adaptations in actual cases suggests grounds of reasonable probability for expecting them in instances as yet untried; and such conjectures in skilful hands are of the utmost utility in physical inquiries; as we often noticed, in the course of our former illustrations.

So long, then, as we confine ourselves to the simple notion of the fact of adjustment, or use, without reference to moral or intellectual causation, we are not departing from sound physical analogies, which we have before contended are the only rational guides in those conjectures which lead to sound inductions.

The Economy of Causes.

ANOTHER instance of the use of final causes in physical investigation, on which much stress has been sometimes laid, is the reference to what has been

called the "lex parsimoniæ," the "economy of causes," or the principle that "nature does nothing in vain ;” or that the most simple means are always adopted for obtaining given ends; or that several powers or agents are never resorted to where one suffices. Such a principle finds its use and application in aid of scientific research, when it is taken as a guide to the more simple in preference to the more complex theory; to known causes rather than imaginary; to hypotheses already applying in other cases rather than new and arbitrary ones; to analogies with existing and established relations rather than to gratuitous suppositions.

Of this kind were the arguments from probability, which weighed most with Copernicus and with Galileo, in favour of the solar system, at a period when no demonstration had been attained; and a more precise exemplification has been found in the argument for the earth's motion in its orbit, and its rotation on its axis, being derived from one and the same primary impulse. It having being shown by Bernouilli, on mechanical principles, that one impulse would produce both, and even the precise point of the earth calculated at which it must have been applied, so as to accord with the existing motions and velocities.

Upon this I will merely observe that the principle referred to, when stated in simple and precise terms, is, in fact, nothing more than the announcement of a great physical and inductive law, the