or the other of two things may happen, is unthinkable. The brain molecules can only move in the determined way; and, if one of them should wander from its place or path without an adequate cause, it would be as great a wonder as if Jupiter should break out from its orbit and throw the planetary system into confusion. If, as monism conceives, our conceptions, efforts, and volitions are really incomprehensible, yet necessary and unequivocal companion-manifestations of the movements and environments of our brain-molecules, there is evidently no freedom of the will. To monism the world is a mechanism, in which there is no place for free-will.
Leibnitz was the first to whom the material world was presented in this form. His mechanical view was quite the same as ours. He was acquainted with the persistence of energy, although he was not able to follow it through all the molecular processes, as we are, and stood toward collective molecular processes as we stand toward single ones. Inasmuch as Leibnitz also firmly believed in a spiritual world, brought the ethical nature of man within the circle of his views, and was on the best of terms with positive religion, it is well to inquire what he believed concerning free-will, and how he was able to reconcile it with the mechanical view of the world.
Leibnitz was obliged by his whole teaching to be an absolute determinist. He accepted two substances as created by God, the material world and the world of his monads. One can not act upon the other, but the processes go on in both under an unalterable, Predetermined necessity, quite independent of each other, but keeping an exact, harmonious step; the mathematically calculable oscillations of the world machine, and, in the soul-monads appertaining to each animated individual, the conceptions that correspond with the apparent sensual impressions, volitions, and conceptions of the host of the monad. The very name of pre-established harmony, which Leibnitz gives to his system, excludes freedom. The conceptions of the monads being mere dream-pictures without mechanical cause or connection with the bodily world, it was easy to explain the subjective conviction of freedom by supposing that God has so ordered the flow of the conceptions of the soul-monad that it believes it is free to act.
On another occasion Leibnitz more closely followed the customary line of thought in allowing to man an appearance of freedom behind which a secret compelling impulse is concealed. Considering in his "Theodicy" the famous paradox, attributed to Buridan, concerning
Which between two bundles of hay"
miserably starved because everything was alike on both sides, and he, as an animal, had no free-will, Leibnitz admitted that, if the case were possible, one would have to decide that he would allow himself to die of hunger; but he held that the case was fundamentally an instance