They are still more frivolous who say, that every effect must have a cause, because 'tis implied in the very idea of effect. Every effect necessarily presupposes a cause; effect being a relative term, of which cause is a correlative. But this does not prove that every being must be preceded by a cause; no more than it follows, because every husband must have a wife, that therefore every man must be married. The true state of the question is, whether every object which begins to exist, must owe its existence to a cause; and this I assert neither to be intuitively nor demonstratively certain, and hope to have proved it sufficiently by the foregoing arguments.
Since it is not from knowledge or any scientific reasoning, that we derive the opinion of the necessity of a cause to every new production, that opinion must necessarily arise from observation and experience. The next question, then, should naturally be, how experience gives rise to such a principle? But as I find it will be more convenient to sink this question in the following, why we conclude, that such particular causes must necessarily have such particular effects, and why we form an inference from one to another? we shall make that the subject of our future inquiry. 'Twill, perhaps, be found in the end, that the same answer will serve for both questions.
[3] Mr Hobbes.
[4] Dr Clarke and others.
[5] Mr Locke.