1. Pleasure and pain, simple ideas.
Amongst the simple ideas which we receive both from sensation and
reflection, pain and pleasure are two very considerable ones. For as in the body there is sensation barely in itself,
or accompanied with pain or pleasure, so the thought or perception of the mind is simply so, or else accompanied
also with pleasure or pain, delight or trouble, call it how you please. These, like other simple ideas, cannot be
described, nor their names defined; the way of knowing them is, as of the simple ideas of the senses, only by
experience. For, to define them by the presence of good or evil, is no otherwise to make them known to us than by
making us reflect on what we feel in ourselves, upon the several and various operations of good and evil upon our
minds, as they are differently applied to or considered by us.
