“IV. Nor is any thing gained by running the difficulty further back, _i. e._ by supposing the watch before us to have been produced by another watch, that from a former, and so on indefinitely. Our going back ever so far brings us no nearer to the least degree of satisfaction upon the subject. Contrivance is still unaccounted for. We still want a contriver. A designing mind is neither supplied by this supposition, nor dispensed with. If the difficulty were diminished the further we went back, by going back indefinitely we might exhaust it. And this is the only case to which this sort of reasoning applies. Where there is a tendency, or, as we increase the number of terms, a continual approach towards a limit, _there_, by supposing the number of terms to be what is called infinite, we may conceive the limit to be attained: but where there is no such tendency or approach, nothing is effected by lengthening the series. There is no difference as to the point in question, (whatever there may be as to many points) between one series and another; between a series which is finite, and a series which is infinite. A chain composed of an infinite number of links, can no more support itself, than a chain composed of a finite number of links. And of this we are assured, (though we never _can_ have tried the experiment) because, by increasing the number of links, from ten for instance to a hundred, from a hundred to a thousand, &c. we make not the smallest approach, we observe not the smallest tendency, towards self-support. There is no difference in this respect (yet there may be a great difference in several respects) between a chain of a greater or less length, between one chain and another, between one that is finite and one that is indefinite. This very much resembles the case before us. The machine, which we are inspecting, demonstrates, by its construction, contrivance and design. Contrivance must have had a contriver; design, a designer; whether the machine immediately proceeded from another machine, or not. That circumstance alters not the case. That other machine may, in like manner, have proceeded from a former machine: nor does that alter the case: contrivance must have had a contriver. That former one from one preceding it: no alteration still: a contriver is still necessary. No tendency is perceived, no approach towards a diminution of this necessity. It is the same with any and every succession of these machines; a succession of ten, of a hundred, of a thousand; with one series as with another; a series which is finite, as with a series which is infinite. In whatever other respects they may differ, in this they do not. In all equally, contrivance and design are unaccounted for.