Page:Treatise of Human Nature (1888).djvu/426

404 from the operation of contrary and conceal'd causes, we conclude, that the chance or indifference lies only in our judgment on account of our imperfect knowledge, not in the things themselves, which are in every case equally necessary, tho' to appearance not equally constant or certain. No union can be more constant and certain, than that of some actions with some motives and characters; and if in other cases the union is uncertain, 'tis no more than what happens in the operations of body, nor can we conclude any thing from the one irregularity, which will not follow equally from the other.

'Tis commonly allow'd that mad-men have no liberty. But were we to judge by their actions, these have less regularity and constancy than the actions of wise-men, and consequently are farther remov'd from necessity. Our way of thinking in this particular is, therefore, absolutely inconsistent; but is a natural consequence of these confus'd ideas and undefin'd terms, which we so commonly make use of in our reasonings, especially on the present subject.

We must now shew, that as the union betwixt motives and actions has the same constancy, as that in any natural operations, so its influence on the understanding is also the same, in determining us to infer the existence of one from that of another. If this shall appear, there is no known circumstance, that enters into the connexion and production of the actions of matter, that is not to be found in all the operations of the mind; and consequently we cannot, without a manifest absurdity, attribute necessity to the one, and refuse it to the other.

There is no philosopher, whose judgment is so riveted to this fantastical system of liberty, as not to acknowledge the force of moral evidence, and both in speculation and practice proceed upon it, as upon a reasonable foundation. Now moral evidence is nothing but a conclusion concerning the actions of men, deriv'd from the consideration of their motives, temper and situation. Thus when we see certain