Pleasure and pain and that which causes them,—good and evil, are the hinges on which our passions turn. And if we reflect on ourselves, and observe how these, under various considerations, operate in us; what modifications or tempers of mind, what internal sensations (if I may so call them) they produce in us we may thence form to ourselves the ideas of our passions.
- Love.
Thus any one reflecting upon the thought he has of the delight which any present or absent thing is apt to produce in him, has the idea we call LOVE. For when a man declares in autumn when he is eating them, or in spring when there are none, that he loves grapes, it is no more but that the taste of grapes delights him: let an alteration of health or constitution destroy the delight of their taste, and he then can be said to love grapes no longer.
- Hatred.
On the contrary, the thought of the pain which anything present or absent is apt to produce in us, is what we call HATRED. Were it my business here to inquire any further than into the bare ideas of our passions, as they depend on different modifications of pleasure and pain, I should remark that our love and hatred of inanimate insensible beings is commonly founded on that pleasure and pain which we receive from their use and application any way to our senses though with their destruction. But hatred or love, to beings capable of happiness or misery, is often the uneasiness of delight which we find in ourselves, arising from their very being or happiness. Thus the being and welfare of a man’s children or friends, producing constant delight in him, he is said constantly to love them. But it suffices to note, that our ideas of love and hatred are but the dispositions of the mind, in respect of pleasure and pain in general, however caused in us.
- Desire.