Principles Of Human Knowledge - pg. 141

But we should proceed warily in such things: for we are apt to lay too great a stress on analogies, and to the prejudice of truth, humour that eagerness of the mind, whereby it is carried to extend its knowledge into general theorems. For example, gravitation, or mutual attraction, because it appears in many instances, some are straightway for pronouncing universal; and that to attract, and be attracted by every other body, is an essential quality inherent in all bodies whatsoever. Whereas it appears the fixed stars have no such tendency towards each other : and so far is that gravitation, from being essential to bodies, that, in some instances a quite contrary principle seems to shew it self : as in the perpendicular growth of plants, and the elasticity of the air. There is nothing necessary or essential in the case, but it depends entirely on the will of the governing spirit, who causes certain bodies to cleave together, or tend towards each other, according to various laws, whilst he keeps others at a fixed distance ; and to some he gives a quite contrary tendency to fly asunder, just as he sees convenient.