That we may fully comprehend the extent of this relation, we must consider, that any principal desire may be attended with subordinate ones, which are connected with it, and to which if other desires are parallel, they are by that means related to the principal one.

Thus hunger may oft be considered as the primary inclination of the soul, and the desire of approaching the meat as the secondary one; since it is absolutely necessary to the satisfying that appetite.

If an object, therefore, by any separate qualities, inclines us to approach the meat, it naturally encreases our appetite; as on the contrary, whatever inclines us to set our victuals at a distance, is contradictory to hunger, and diminishes our inclination to them.

Now it is plain that beauty has the first effect, and deformity the second: Which is the reason why the former gives us a keener appetite for our victuals, and the latter is sufficient to disgust us at the most savoury dish that cookery has invented.

All this is easily applicable to the appetite for generation.
From these two relations, viz, resemblance and a parallel desire, there arises such a connexion betwixt the sense of beauty, the bodily appetite, and benevolence, that they become in a manner inseparable: And we find from experience that it is indifferent which of them advances first; since any of them is almost sure to be attended with the related affections.