ONE:Be this as it may, Spinoza takes up the Aristotelian identification of logical with dynamical connexion, and gives it the widest possible development. For the Stagirite would not, at any rate, have dreamed of attributing any but a subjective existence to the demonstrative series, nor of extending it beyond the limits of our actual knowledge. Spinoza, on the other hand, assumes that the whole infinite chain of material causes is represented by a corresponding chain of eternal ideas; and this chain he calls the infinite intellect of God.566 Here, besides the necessities of systematisation, the411 influence of mediaeval realism is plainly evident. For, when the absolute self-existence of Platos Ideas had been surrendered in deference to Aristotles criticism, a home was still found for them by Plotinus in the eternal Nous, and by the Christian Schoolmen in the mind of God; nor did such a belief present any difficulties so long as the divine personality was respected. The pantheism of Spinoza, however, was absolute, and excluded the notion of any but a finite subjectivity. Thus the infinite intellect of God is an unsupported chain of ideas recalling the theory at one time imagined by Plato.567 Or its existence may be merely what Aristotle would have called potential; in other words, Spinoza may mean that reasons will go on evolving themselves so long as we choose to study the dialectic of existence, always in strict parallelism with the natural series of material movements constituting the external universe; and just as this is determined through all its parts by the totality of extension, or of all matter (whether moving or motionless) taken together, so also at the summit of the logical series stands the idea of God, from whose definition the demonstration of every lesser idea necessarily follows. It is true that in a chain of connected energies the antecedent, as such, must be always precisely equal to the consequent; but, apparently, this difficulty did not present itself to Spinoza, nor need we be surprised at this; for Kant, coming a century later, was still so imbued with Aristotelian traditions as, similarly, to derive the category of Cause and Effect from the relation between Reason and Consequent in hypothetical propositions.568Returning to Epicurus, we have next to consider how he obtained the various motions required to bring his atoms into those infinite combinations of which our world is only the most recent. The conception of matter naturally endowed with capacities for moving in all directions indifferently was unknown to ancient physics, as was also that of mutual attraction and85 repulsion. Democritus supposed that the atoms all gravitated downward through infinite space, but with different velocities, so that the lighter were perpetually overtaken and driven upwards by the heavier, the result of these collisions and pressures being a vortex whence the world as we see it has proceeded.163 While the atomism of Democritus was, as a theory of matter, the greatest contribution ever made to physical science by pure speculation, as a theory of motion it was open to at least three insuperable objections. Passing over the difficulty of a perpetual movement through space in one direction only, there remained the self-contradictory assumption that an infinite number of atoms all moving together in that one direction could find any unoccupied space to fall into.164 Secondly, astronomical discoveries, establishing as they did the sphericity of the earth, had for ever disproved the crude theory that unsupported bodies fall downward in parallel straight lines. Even granting that the astronomers, in the absence of complete empirical verification, could not prove their whole contention, they could at any rate prove enough of it to destroy the notion of parallel descent; for the varying elevation of the pole-star demonstrated the curvature of the earths surface so far as it was accessible to observation, thus showing that, within the limits of experience, gravitation acted along convergent lines. Finally, Aristotle had pointed out that the observed differences in the velocity of falling bodies were due to the atmospheric resistance, and that, consequently, they would all move at the same rate in such an absolute vacuum as atomism assumed.165 Of these objections Epicurus ignored the first two, except, apparently, to the extent of refusing to believe in the antipodes. The third he acknowledged, and set himself to evade it by a hypothesis striking at the root of all scientific86 reasoning. The atoms, he tells us, suffer a slight deflection from the line of perpendicular descent, sufficient to bring them into collision with one another; and from this collision proceeds the variety of movement necessary to throw them into all sorts of accidental combinations. Our own free will, says Lucretius, furnishes an example of such a deflection whenever we swerve aside from the direction in which an original impulse is carrying us.166 That the irregularity thus introduced into Nature interfered with the law of universal causation was an additional recommendation of it in the eyes of Epicurus, who, as we have already mentioned, hated the physical necessity of the philosophers even more than he hated the watchful interfering providence of the theologians. But, apparently, neither he nor his disciples saw that in discarding the invariable sequence of phenomena, they annulled, to the same extent, the possibility of human foresight and adaptation of means to ends. There was no reason why the deflection, having once occurred, should not be repeated infinitely often, each time producing effects of incalculable extent. And a further inconsequence of the system is that it afterwards accounts for human choice by a mechanism which has nothing to do with free-will.167
Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas.
