ry manner the charge brought against Bacon by Cudworth, contains some very just remarks on the improper application made by the Peripatetics and their followers, of the speculation concerning final causes,--an abuse which they carried so far as to justify Bacon, in a work expressly destined to illustrate the true method of inquiry in physics, to propose the complete rejection of that speculation from natural philosophy.

In the present age, when the true method of philosophizing is pretty generally understood, and when philosophers seem more in danger of going wrong in natural theology than in natural philosophy, it does not appear to me to be so necessary as formerly to banish final causes from physics, provided always they are kept distinct from physical causes, with which they are scarcely in any danger (in the present state of science) of being confounded. What harm can possibly result from the natural philosopher's remarking those instances of design which fall under his review in the course of his inquiries? Or if it should be considered as foreign to his province to speak of design, he may at least be permitted to remark what ends are really accomplished by particular means, and what advantages are derived by man from the general laws by which the phenomena of nature are regulated. In doing this, he only states a fact; and if it be improper for him to go further, he may leave the inference to the moralist or to the divine.

In consequence, however, of the vague and common place declamation against the use of final causes in physics, countenanced by those detached expressions of Bacon, which have suggested the foregoing reflections, it has become fashionable among philosophers to omit the consideration of them entirely, as a speculation inconsistent with the genuine spirit of inductive science; a caution (it may be remarked by the way) which is the most scrupulously observed by those writers who are the most forward to remark every apparent anomaly or disorder in the economy of the universe. The effect of this has been to divest the study of nature Jo its most attractive charms, and to sacrifice to a false

idea of logical rigor all the moral impressions and pleasures which it is fitted to yield; and even, when the most striking accommodation of means to an end force themselves upon the mind, to take no notice of such facts in their physical speculations. Nay, what is worse, those writers who are the most forward to remark every apparent irregularity in the universe never fail to remind us (if at any time we seem to be struck with appearances of order and of wisdom) that the consideration of final causes is altogether exploded by that inductive philosophy which Bacon recommended, and to which we are indebted for the sublime discoveries of Newton and his followers. Indeed, this scholastic phrase has become so obnoxious, that it were to be wished it could be laid aside, and some simpler mode of speaking, such as ends or uses, substituted instead of it. In the mean time, it may contribute to smooth the way for such a change in phraseology to employ indiscriminately these different terms as synonymous and convertible expressions.

To this we may add, that there are some parts of nature which we cannot be said to understand as philosophers, without the consideration of uses. This is remarkably the case in the study of anatomy. To know the structure of the body of an animal we must not only examine the conformation of the parts, but we must consider their functions, and in what way they conspire to the preservation and health of the animal.* I am inclined to think that it is by means of the consideration of uses that the principal anatomical discoveries have been made. Every anatomist in his inquiries proceeds upon the maxim, that nothing in the body of an animal was made in vain; and when he meets with something, the use of which is not obvious, he feels himself dissatisfied till he discovers some at least of the purposes to which it is subservient. We have one remarkable instance of this recorded by Mr. Boyle.

"I remember that when I asked our famous Harvey, in the only discourse I had with him, (which was but a lit

Consult on this subject a paper by Dr. John Wallis, and another by Dr. Tyson in the Philosophical Transactions, No. 269. For a short account of them see Philosophical Transactions, (from 1700 to 1720) abridged, Vol. V. p. 1, et seq.

tle while before he died) what were the things which induced him to think of a circulation of the blood? He answered me, that when he took notice that the valves in the veins of so many parts of the body were so placed, that they gave free passage to the blood towards the heart, but opposed the passage of the venal blood the contrary way, he was invited to think that so provident a cause as nature had not placed so many valves without design, and no design seemed more probable than that since the blood could not well, because of the interposing valves, be sent by the veins to the limbs, it should be sent through the arteries, and return through the veins, whose valves did not oppose its course that way.'

In general, it may be observed that those philosophers who have been most successful in detecting the secrets of nature have been men strongly impressed with the general idea of prevailing order and of benevolent design; and I have no doubt that this impression contributed greatly to enlighten their views and to guide their investigations. It is remarked by Dr. Priestley, (a writer whose opinion on this question is of great value, from the signal success of his own experimental inquiries) "that, as true philosophy tends to promote piety, so a generous and manly piety is reciprocally subservient to the purposes of philosophy; for while we keep in view the great FINAL Cause of all the parts and the laws of nature, we have a clue by which to trace the efficient cause." To the same purpose Priestley quotes the following remark of Hartley in his Observations on Man. "Since this world is a system of benevolence, and consequently its Author the object of unbounded love and adoration, benevolence and piety are our only true guides in our inquiries into it, the only keys which will unlock the mysteries of nature, and clues which lead through her labyrinths. Of this all branches of natural philosophy and natural history afford abundant instances. In all these inquiries let the inquirer take it for granted previously that every thing is right, and the best that

Boyle's Works, Vol. IV. folio, p. 539. For some remarks on this anecdote by the late celebrated anatomist, Dr. William Hunter, see Philosophy of the Human Mind, vol. ii. pp. 487, 488. Third Edition.

can be cæteris manentibus; that is, let him with a pious confidence seek for benevolent purposes, and he will be always directed to the right road, and after a due continuance in it attain to some new and valuable truth: Whereas every other principle of examination being foreign to the great plan on which the universe is constructed, must lead into endless mazes, errors, and perplexities." *

Having said so much about the research of final causes in physics, I shall subjoin a few reflections on its application to the Philosophy of the Human Mind; a science in which the just rules of investigation are as yet far from being completely understood. Of this no stronger proof can be produced than the confusion between final and efficient causes which still prevails in the writings of our most eminent moralists. The same confusion, as I have already observed, may be traced in the physical theories of the schoolmen; but since the time of Bacon it has been so completely corrected, that, in the wildest hypothesis of the eighteenth century, hardly a vestige of it is to be found.

To the logical error just mentioned it is owing that so many false accounts have been given of the principles of human conduct, or of the motives from which our actions proceed. When the general laws of our constitution are attentively examined, they will be found to have for their object the happiness and improvement both of the individual and of society. This is their final cause, or the end for which we may presume they were destined by our Maker. But in such cases it seldom happens, that, while man is obeying the active impulses of his nature, he has any idea of the ultimate ends he is promoting, or is able to calculate the remote effects of those little wheels which he puts into motion. These active impulses may therefore in one sense be considered as the efficient causes of his conduct; inasmuch as they are the means employed to determine him to a particular course of action, and as they operate, at least in the first instance, without any reflection on his part on the ends to which they are subservient. Philosophers, however,

Preface to Priestley's History of Electricity.

have in every age been extremely apt, when they had discovered the salutary tendency of any principle of action, to conclude that the principle derived its origin from a sense of this tendency. Hence have arisen the theories which attempt to account for all our actions from self-love, and also those which would resolve the whole of morality into views of utility.

I do not know of any author who has been more completely aware of this common error than Mr. Smith, who, in his Theory of Moral Sentiments, always treats separately of the final causes of the different principles he considers, and of the mechanism (as he calls it) by which nature accomplishes the effect. The following profound remarks show sufficiently the opinion he had of the great importance of attending to the distinction between them.

"In every part of the universe we observe means adjusted with the nicest artifice to the ends which they are intended to produce, and in the mechanism of a plant or animal body admire how every thing is contrived for advancing the two great purposes of nature, the support of the individual, and the propagation of the species. But in these, and in all such objects, we still distinguish the efficient from the final cause of their several motions and organizations. The digestion of the food, the circulation of the blood, and the secretion of the several juices which are drawn from it, are operations all of them necessary for the great purposes of animal life, yet we never endeavour to account for them from those purposes, as from their efficient causes; nor imagine that the blood circulates, or that the food digests of its own accord, with a view or intention to the purposes of circulation or digestion. The wheels of the watch are all admirably adapted to the end for which it was made, the pointing of the hour. All their various motions conspire in the nicest manner to produce this effect. If they were endowed with a desire and intention to produce it, they could not do better. Yet we never ascribe any such intention or desire to them, but to the watchmaker; and we know that they are put into motion by a spring, which intends the effect it produces as little as they do. But, though, in accounting for the operations of bodies,