Dr. Priestley is right in his opinion that this question was not understood by the ancients, nor perhaps before the time of Hobbes: Long ago it appeared to me, that the only writer among the schoolmen who had touched upon it, was Bradwardine in his Book De causà Dei, which I regret that I have no opportunity of consulting here. Many of his observations are extracted by Toplady in his treatise on Liberty and Necessity, and in his life of Zanchius; but Toplady like Edwards, did not completely understand the question; they connected the doctrine of necessity with all the bigotry of Calvinism. Hobbes in his Leviathan, and in his reply to Bramhall on liberty and necessity in his Tripos, first truly stated the subject, and shewed that the question was, not whether we can do what we will, but whether the will itself, (i. e. choice, preference, inclination, desire, aversion,) is not inevitably determined by motives not in the power or controul of the agent. Hartley’s book, however, shews, or rather leads to the conclusion, that these motives are twofold, _ab extra_ and _ab intra_. The action depending on the compound force of the motives ab extra, and the physical state of the animal organs at the moment. For the latter is frequently of itself an immediate cause of voluntary action. But previous to Dr. Hartley’s great work, the question of liberty and necessity had been discussed between Collins and Clark, and Clark and Leibnitz.[71] Collins’s Philosophical inquiry into human liberty, first published in 1715 was the only book on the subject worth reading between the times of Hobbes and Hartley, and a masterly and decisive work it is. This appears to have been translated and repeatedly printed on the continent; Dr. Priestley, who republished it in London, mentioning a second edition in 1756 at Paris, and a third edition when he was there in 1774. The controversy was kept alive in Collins’s life time by Leibnitz; but he like Dr. Edwards who afterwards wrote in defence of the same side of the question in his treatise on Free will, was too much given to expand his ideas, and obscure the sense by the multiplicity of words which he used to express it. The letters of Theodicèe contain many passages well conceived, but the book is insupportably tedious. Hobbes could condense more argument and information in a page, than would serve Leibnitz for a volume. [71] I do not find that the controversy about the Soul occasioned by the publications of Blount, Coward, Dodwell, &c. involved the question of Liberty and Necessity, though they touch so nearly. It escaped me a few pages back, that Dr. Coward, was also the author of “Second Thoughts concerning the human Soul.” (Estibius Psycalethes) as well as of the Grand Essay.