In order to this I consider, in what objects necessity is commonly supposed to lie; and finding that it is always ascribed to causes and effects, I turn my eye to two objects supposed to be placed in that relation; and examine them in all the situations, of which they are susceptible.

I immediately perceive, that they are contiguous in time and place, and that the object we call cause precedes the other we call effect.

In no one instance can I go any farther, nor is it possible for me to discover any third relation betwixt these objects.

I therefore enlarge my view to comprehend several instances; where I find like objects always existing in like relations of contiguity and succession.

At first sight this seems to serve but little to my purpose.