That idea arises im- mediately.

That idea arises im- mediately. The thought moves instantly towards it, and conveys to it all that force of conception, which is derived from the impression present to the senses. When a sword is levelled at my breast, does not the idea of wound and pain strike me more strongly, than when a glass of wine is presented to me, even though by accident this idea should occur after the appearance of the latter object?

But what is there in this whole matter to cause such a strong conception, except only a present object and a customary transition of the idea of another object, which we have been accustomed to conjoin with the former? This is the whole operation of the mind, in all our conclusions con- cerning matter of fact and existence; and it is a satisfaction to find some analogies, by which it may be explained.

The transition from a present object does in all cases give strength and solidity to the related idea. Here, then, is a kind of pre-established harmony between the course of nature and the succession of our ideas; and though the powers and forces, by which the former is gov- erned, be wholly unknown to us; yet our thoughts and conceptions have still, we find, gone on in the same train with the other works of nature.

Custom is that principle, by which this correspondence has been effected; so neces- sary to the subsistence of our species, and the regulation of our conduct, in every circumstance and occurrence of hu- man life.

Had not the presence of an object, instantly excited the idea of those objects, commonly conjoined with it, all our knowledge must have been limited to the narrow sphere of our memory and senses; and we should never have been able to adjust means to ends, or employ our natural powers, either to the producing of good, or avoiding of evil. Those, who delight in the discovery and contem- plation of final causes, have here ample subject to employ their wonder and admiration.

I shall add, for a further confirmation of the foregoing theory, that, as this operation of the mind, by which we infer like effects from like causes, and vice versa, is so essential to the subsistence of all human creatures, it is not probable, that it could be trusted to the fallacious de- ductions of our reason, which is slow in its operations; appears not, in any degree, during the first years of infancy; and at best is, in every age and period of human life, ex- tremely liable to error and mistake.