To this I reply, that in judging of the actions of men we must proceed upon the same maxims, as when we reason concerning external objects. When any phaenomena are constantly and invariably conjoined together, they acquire such a connexion in the imagination, that it passes from one to the other, without any doubt or hesitation. But below this there are many inferior degrees of evidence and probability, nor does one single contrariety of experiment entirely destroy all our reasoning. The mind ballances the contrary experiments, and deducting the inferior from the superior, proceeds with that degree of assurance or evidence, which remains. Even when these contrary experiments are entirely equal, we remove not the notion of causes and necessity; but supposing that the usual contrariety proceeds from the operation of contrary and concealed 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, though 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, it is 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.
It is commonly allowed 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 removed from necessity. Our way of thinking in this particular is, therefore, absolutely inconsistent; but is a natural consequence of these confused ideas and undefined 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 into 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, derived from the consideration of their motives, temper and situation. Thus when we see certain characters or figures described upon paper, we infer that the person, who produced them, would affirm such facts, the death of Caesar, the success of Augustus, the cruelty