convert them into incentives and temptations. So that all the desires, designs, and ideas of such persons are tainted with lust. However, the diseases and sufferings, bodily and mental, which this vice brings upon men, do, after some time, often check the exorbitancy of it, still in the way of association. But impure desires subsist, like vicious ones of other kinds, long after the pains outweigh the pleasures, inasmuch as they must be supposed not to begin to decline till the pains apprehended to arise from them, and thus associated with them, become equal to the pleasures.
Tenthly, It appears from the course of reasoning here used, that impure and vicious desires, indulged and heightened voluntarily, can by no means consist with a particular attachment and confinement; also that they must not only end frequently in indifference, but even in hatred and abhorrence. For the proper mental sources of affection are not only wanting in these cases, but many displeasing and odious qualities and dispositions of mind must offer themselves to view by degrees.
Eleventhly, As the desires and pleasures of this kind are thus increased by associated influences from other parts of our natures, so they are reflected back by innumerable associated methods, direct and indirect, upon the various incidents and events of life, so as to affect in secondary ways even those who have never experienced the gross corporeal gratification. And, notwithstanding the great and public mischiefs, which arise from the ungovernable desires of the vicious, there is great reason, even from this theory, to apprehend, that if this source of the benevolent affections was cut off, all other circumstances remaining the same, mankind would become much more selfish and malicious, much more wicked and miserable, upon the whole, than they now are.
Twelfthly, I have hitherto chiefly considered how far the present subject is agreeable to the doctrine of association; but if physicians and anatomists will compare the circumstances of the sensations and motions of these organs with the general theory delivered in the first chapter, they may see considerable evidences for sensory vibrations, for their running along membranes, and affecting the neighbouring muscles in a particular manner: they may see also, that muscular contractions, which are nearly automatic at first, become afterwards subject to the influence of ideas.
Thirteenthly, The theory here proposed for explaining the nature and growth of these desires shews in every step, how watchful every person, who desires true chastity and purity of heart, ought to be over his thoughts, his discourses, his studies, and his intercourses with the world in general, and with the other sex in particular. There is no security but in flight, in turning our minds from all the associated circumstances, and begetting a new train of thoughts and desires, by an honest,
