to-day, though this mutilation and leveling down of the most daring of Leibnitz’s hypotheses was perhaps entirely advantageous for Wolff’s impression on his contemporaries; what appeared questionable to him would no doubt have repelled them also.  Leibnitz’s two leading ideas, the theory of monads and the pre-established harmony, were most of all affected by this process of toning down.  Wolff weakens the former by attributing a representative power only to actual souls, which are capable of consciousness, although he holds that bodies are compounded of simple beings and that the latter are endowed with (a not further defined) force.  He limits the application of the pre-established harmony to the relation of body and soul, which to Leibnitz was only a case especially favorable for the illustration of the hypothesis.  By such trifling the real meaning of both these ideas is sacrificed and their bloom rubbed off.—­While depth is lacking in Wolff’s thinking, he is remarkable for his power of systematization, his persevering diligence, and his logical earnestness, so that the praise bestowed on him by Kant, that he was the author of the spirit of thoroughness in Germany, was well deserved.  He, too, finds the end of philosophy in the enlightenment of the understanding, the improvement of the heart, and, ultimately, in the promotion of the happiness of mankind.  But while Thomasius demanded as a condition of such universal intelligibility and usefulness that, discarding the scholastic garb, philosophy should appear in the form of easy ratiocination, Wolff, on the other hand, regards methodical procedure and certainty in results as indispensable to its usefulness, and, in order to this certainty, insists on distinctness of conception and cogency of proof.  He demands a philosophia et certa et utilis.  If, finally, his methodical deliberateness, especially in his later works, leads him into wearisome diffuseness, this pedantry is made good by his genuinely German, honest spirit, which manifests itself agreeably in his judgment on practical questions.

[Footnote 1:  Reasonable Thoughts on the Powers of the Human Understanding, 1712; Reasonable Thoughts on God, the World, and the Soul of Man, also on All Things in General, 1719 (Notes to this 1724); Reasonable Thoughts on the Conduct of Man, 1720; Reasonable Thoughts on the Social Life of Man, 1721; Reasonable Thoughts on the Operations of Nature, 1723; Reasonable Thoughts on the Purposes of Natural Things, 1724; Reasonable Thoughts on the Parts of Man, Animals, and Plants, 1725, all in German.  Besides these there are extensive Latin treatises (1728-53) on Logic, Ontology, Cosmology, Empirical and Rational Psychology, Natural Theology, and all branches of Practical Philosophy.  Detailed extracts may be found in Erdmann’s Versuch einer wissenschaftlichen Darstellung, ii. 2.  The best account of the Wolffian philosophy has been given by Zeller (pp. 211-273).]