We associate the food with the gratification of these demands, and hence food becomes an end to us--one of the _associated_ or _intermediate_ ends.

So the desire of knowledge is the desire of the pleasure, or of the relief from pain, accruing from knowledge; while, as in the case of food, knowledge is to a great degree only an instrument, and therefore an intermediate and associated end.

So the desire of esteem is the desire of a pleasure, or else of the instrument of pleasure.
In short, Butler tries, without effect, to evade the general principles of the will--our being moved exclusively by pleasure and pain.

Abundant reference has been already made to the circumstances that modify in appearance, or in reality, the operation of this principle.

The distinction between self-love and the particular appetites, passions, and affections, is mainly the distinction between a great aggregate of the reason (the total interests of our being) and the separate items that make it up.
The distinction is intended to prepare the way for the setting forth of Conscience,[21] which is called a 'principle of reflection in men, whereby they distinguish between, approve and disapprove, their own actions.' This principle has for its result the good of society; still, in following it, we are not conscious of aiming at the good of society.
A father has an affection for his children; this is one thing.