Whatever be the cause, it is an established fact, that we are much influenced by custom. It hath an effect upon our pleasures, upon our actions, and even upon our thoughts and sentiments. Habit makes no figure during the vivacity of youth; in middle age it gains ground; and in old age it governs without control. In that period of life, generally speaking, we eat at a certain hour, take exercise at a certain hour, go to rest at a certain hour, all by the direction of habit. Nay a particular seat, table, bed, comes to be essential. And a habit in any of these, cannot be contradicted without uneasiness. Any slight or moderate pleasure frequently reiterated for a long time, forms a connection betwixt us and the thing that causes the pleasure. This connection, termed _habit_, has the effect to raise our desire or appetite for that thing when it returns not as usual. During the course of enjoyment, the pleasure grows insensibly stronger till a habit be established; at which time the pleasure is at its height. It continues not however stationary. The same customary reiteration which carried it to its height, brings it down again by insensible degrees, even lower than it was at first. But of this circumstance afterward. What at present we have in view, is to prove by experiments, that those things which at first are but moderately agreeable, are the aptest to become habitual. Spirituous liquors, at first scarce agreeable, readily produce an habitual appetite; and custom prevails so far, as even to make us fond of things originally disagreeable, such as coffee, assa-sœtida, and tobacco. This is pleasantly illustrated by Congreve: _Fainall._ For a passionate lover, methinks you are a man somewhat too discerning in the failings of your mistress. _Mirabell._ And for a discerning man, somewhat too passionate a lover; for I like her with all her faults; nay like her for her faults. Her follies are so natural, or so artful, that they become her; and those affectations which in another woman would be odious, serve but to make her more agreeable. I’ll tell thee, Fainall, she once us’d me with that insolence, that in revenge I took her to pieces, sifted her, and separated her failings; I study’d ’em, and got ’em by rote. The catalogue was so large, that I was not without hopes, one day or other, to hate her heartily: to which end I so us’d myself to think of ’em, that at length, contrary to my design and expectation, they gave me every hour less and less disturbance; till in a few days it became habitual to me, to remember ’em without being displeased. They are now grown as familiar to me as my own frailties; and in all probability, in a little time longer, I shall like ’em as well. _The way of the world, act 1. sc. 3._