I have hitherto purposely avoided saying any thing on the subject of our physical appetites and the manner in which they may be thought to affect the principle of the foregoing reasonings. They evidently seem at first sight, to contradict the general conclusion which I have endeavoured to establish, as they all of them tend either exclusively or principally to the gratification of the individual, and at the same time refer to some future or imaginary object, as the source of this gratification. The impulse which they give to the will is mechanical, and yet this impulse, blind as it is, constantly tends to and coalesces with the pursuit of some rational end. That is, here is an end aimed at, the desire and regular pursuit of a known good, and all this produced by motives evidently mechanical, and which never impel the mind but in a selfish direction: it makes no difference in the question whether the active impulse proceed directly from the desire of positive enjoyment, or a wish to get rid of some positive uneasiness. I should say then that, setting aside what is of a purely physical nature in the case, the influence of appetite over our volitions may be accounted for consistently enough with the foregoing hypothesis, from the natural effects of a particularly irritable state of bodily feeling, rendering the idea of that which will heighten and gratify its susceptibility of pleasurable feeling, or remove some painful feeling, proportionably vivid, and the object of a more vehement desire than can be excited by the same idea, when the body is supposed to be in a state of indifference, or only ordinary sensibility to that particular kind of gratification. Thus the imaginary desire is sharpened by constantly receiving supplies of pungency, from the irritation of bodily feeling, and its direction is at the same time determined according to the bias of this new impulse; first, indirectly by having the attention fixed on our own immediate sensation; secondly, because that particular gratification, the desire of which is increased by the pressure of physical appetite, must be referred primarily and by way of distinction to the same being, by whom the want of it is felt, that is, to myself. As the actual uneasiness which appetite implies can only be excited by the irritable state of my own body, so neither can the desire of the correspondent gratification subsist in that intense degree, which properly constitutes appetite, except when it tends to relieve that very same uneasiness by which it was excited, as in the case of hunger. There is in the first place the strong mechanical action of the nervous and muscular systems co-operating with the rational desire of my own belief, and forcing it its own way. Secondly, this state of uneasiness grows more and more violent, the longer the relief which it requires is withheld from it: hunger takes no denial, it hearkens to no compromise, is soothed by no flattery, tired out by no delay. It grows more