ONE:[Pg 20]Yet if teleology was, in some respects, a falling-off from the rigid mechanicism first taught by the pre-Socratic schools and then again by the Cartesian school, in at least one respect it marked a comparative progress. For the first attempts made both by ancient and modern philosophy to explain vital phenomena on purely mechanical principles were altogether premature; and the immense extension of biological knowledge which took place subsequently to both, could not but bring about an irresistible movement in the opposite direction. The first to revive teleology was Leibniz, who furnished a transition from the seventeenth to the eighteenth century by his monadology. In this, Atomism is combined with Aristotelian ideas, just as it had previously been combined with Platonic ideas by Descartes. The movement of the atoms is explained by their aspiration after a more perfect state instead of by mechanical pressure. But while Leibniz still relies on423 the ontological argument of Descartes to prove the existence of God, this was soon abandoned, along with the cosmological argument, for the argument from design, which was also that used by the Stoics; while in ethics the fitness of things was substituted for the more mechanical law of self-preservation, as the rule of conduct; and the subjection of all impulse to reason was replaced by the milder principle of a control exercised by the benevolent over the malevolent instincts. This was a very distinct departure from the Stoic method, yet those who made it were more faithful to teleology than Stoicism had been; for to condemn human feeling altogether was implicitly to condemn the work of Nature or of God.

---