motions of the fluids and solids of the body which accompany any passion; or the temperaments of body, which either make men prone to any passion, or are brought upon us by the long continuance or frequent returns of it. ’Tis only to our purpose, in general, to observe, That probably certain motions of the body do accompany every passion by a fixed law of nature, and alternately, that temperament which is apt to receive or prolong these motions in the body, does influence our passions to heighten or prolong them. Thus a certain temperament may be brought upon the body by its being frequently put into motion by the passions of anger, joy, love or sorrow; and the continuance of this temperament make men prone to these several passions for the future.” Were this dependence of the body and mind more studied, and its effects collected and ranged into proper order; no doubt, we would be able to form a better judgment of it, and see further into the good purposes to which it serves; for the greater advances have hitherto been made in any branches of physical<78> philosophy, the more instances do we perceive of excellent contrivance and kind oeconomy.
Mean time, it is evident, that such a dependence is involved in the very idea of union of mind with body.
II. Mean time, as the fact, in general, is certain from many experiments, so it is evident, there can be no mutual union of body and mind without reciprocal dependence; and their reciprocal dependence cannot take place without laws, fixing and determining connexions between all the possible changes in the body, and certain correspondent changes in the mind; and alternately between all possible conditions of the mind, and certain correspondent alterations in the bodily part. All this is involved in the very notion of regular and mutual dependence. Consequently the only question with regard to our present union with a material world by means of our bodies is, 1. Whether, in consequence of these laws, we are not capable of very considerable pleasures, which otherwise could not possibly have place in nature? for did we not exist, in the present embodied state we are now in, the sensible world we are capable of enjoying in so many different ways, as rational as well as sensitive beings, could not exist. And, 2. Whether the pains we suffer, in consequence of this union, be not the necessary effects of the union itself, and the best, that is, the fitest admonitions we can have of what is necessary to our sustenance and well-being? for such pains cannot be called evils with respect to the whole system; but, on the contrary, being the effects of good general laws, are goods. To both which questions a sufficient answer hath been given.
The good consequence of this dependence of our minds on body and physical connexions.
III. To all which let it be added, that from the dependence of our mind upon body and physical causes, there arises this good consequence, “That, whereas the tempers, characters, abilities, and dispositions of our minds, would be utterly unalterable by us, if they were not dependent in that manner upon us; being<79> so dependent, they may in a great measure be changed by our own proper care; or to do so only requires, that we should give due attention to the natural connexions on which they depend; and conformably to them take proper measures to make fit changes.” That is to say, changing and reforming our minds, as far as mind depends upon body, depends on ourselves, because it depends upon knowledge of nature we may acquire, and right use of such knowledge. It is often regreted by ancient philosophers,a that the dependence of body and mind, as evidently as its extent discovers itself in many cases, is so little studied and enquired into by philosophers. Were it, say they, more carefully attended to and considered, the medicinal art would extend further than to the body: it would be able to do great services to the mind, by proper applications to the body, or by proper external regimens and discipline. Upon this occasion, they have expressed a very high opinion, not only of certain gymnastic exercises, but of the power of music in particular; and seem to think, that very advantageous uses might be made of that art, in several cases, for delivering the mind from disorders; or for purging and refining the passions; calming, quieting, cheering, and strengthning the mind.
True morality must therefore consider man as a compound creature; or his body and mind as reciprocally dependent.
But let that be as it will, tho’ the science we have now been speaking of (the medicine of the mind, and that part of natural knowledge, from which alone it can be deduced) be very much neglected, yet from what hath been said of the dependence of<80> body and mind, it plainly appears, why the best ancient moralists, as well as the christian religion, recommend severe bodily discipline, in order to form, establish, preserve, and corroborate virtuous habits. Such must the morality be that belongs to beings of our compound make. Precepts not inferred from the human constitution, must be idle and vain, they cannot appertain to us. To forget in directions about our conduct, that we are rational beings, is indeed to forget our most essential and noble part: but, on the other hand, to forget in moral precepts, that we are likewise sensitive, embodied beings, is to leave out in morality, which ought to be founded upon the nature of beings, a very essential and important part of our make. It is therefore no wonder, if such morality prescribes rules to us, that are either above our practice, or insufficient to gain that purpose which ought to be the end of all rules relative to our conduct; namely, acting agreeably to our frame, or in a manner becoming our rank and conducive to our happiness. That must necessarily be the case, when our make is not strictly kept in view, in laying down precepts for our observance. Now this is plainly our rank; we are neither wholly moral, nor wholly sensitive beings; but a compound of moral and sensitive powers and affections reciprocally dependent upon one another: man is, as some philosophers have very properly expressed it; Nexus utriusque mundi.33 And the excellence of the christian morality consists in this, that in all its precepts man is considered and advised as such a being.
The bliss of man (could pride that blessing find)
Is not to act, or think beyond mankind;
No pow’rs of body, or of soul to share,
But what his nature, and his state can bear.
Essay on man, Epist. 1.34<81>
General conclusion concerning their laws.
All the observations that have been made by natural philosophers upon the animal oeconomy of the human body, the different bodily oeconomies of other animals suited to their various states, and, in general, upon the wise contrivance and good order of the sensible world might very properly have been collected and inserted here. But the preceeding remarks will prepare every intelligent reader for making a proper use, and seeing the full extent of such observations; and from what has been said, we may justly conclude, “That the laws relating to our embodied state, and our connexion with the material or sensible world, are either necessary or fit: many excellent effects result from them, and none of the effects of good general laws can be evil, absolutely considered, that is, with respect to the whole.”
A third class of laws.
Let us proceed to consider the laws of our nature relative to the association of ideas, and the formation of habits.
These relative to the association of ideas and habits.
There are two things very remarkable in our nature; “The association of ideas, or the difficulty with which ideas that have been often presented to the mind together are afterwards disjoined;” and, “The formation of habits by repeated acts; or a facility in doing, and a propension to reiterate the same action contracted by frequent doing it.”
Both these take their rise from one principle.
These two effects are very similar or like: they both include in their nature a certain kind of cohesion with the mind, formed by reiterated conjunction or co-existence between objects really separate and distinct from one another; i.e. that do not necessarily
