[Footnote 1: Chr. Sturm: Physica Conciliatrix, 1687; Physica Electiva, vol. i. 1697, vol. ii. with preface by Chr. Wolff, 1722; Compendium Universalium seu Metaphysica Euclidea.]
[Footnote 2: J. Jung Logica Hamburgiensis, 1638; cf. Guhrauer, 1859.]
[Footnote 3: Pufendorf: Elementa Juris Universalis, 1660; De Statu Imperii Germanici, 1667, under the pseudonym Monzambano; De Jure Natures et Gentium 1672, and an abstract of this, De Officio Hominis et Civis, 1673.]
Pufendorf was followed by Christian Thomasius[1] (1655-1728; professor of law at the University of Halle from its foundation in 1694). He was the first instructor who ventured to deliver lectures in the German language—in Leipsic from 1687—and at the same time was the editor of the first learned journal in German (Teutsche Monate, Geschichte der Weisheit und Thorheit). In Thomasius the characteristic features of the German Illumination first came out in full distinctness, namely, the avoidance of scholasticism in expression and argument, the direct relation of knowledge to life, sober rationality in thinking, heedless eclecticism, and the demand for religious tolerance. Philosophy must be generally intelligible, and practically useful, knowledge of the world (not of God); its form, free and tasteful ratiocination; its object, man and morals; its first duty, culture, not learning; its highest aim, happiness; its organ and the criterion of every truth, common sense. He alone gains true knowledge who frees his understanding from prejudice and judges only after examining for himself; the joy of mental peace is given to no one who does not free his heart from foolish desires and vehement passions, and devote it to virtue, to "rational love." The positive doctrines of Thomasius have less interest than this general standpoint, which prefigured the succeeding period. He divides practical philosophy into natural law which treats of the justum, politics which treats of the decorum, and ethics which treats of the honestum. Justice bids us, Do not to others what you would not that others should do to you; decorum, Do to others as you would that they should do to you; and morality, Do to yourself as you would that others should do to themselves. The first two laws relate to external, the third to internal, peace; legal duties may be enforced by compulsion, moral duties not.
[Footnote 1: Thomasius: Institutionum Jurisprudentiae Divinae Libri Tres, 1688; Fundamenta Juris Naturae et Gentium, 1705, both in Latin; in German, appeared in 1691-96 the Introduction and Application of Rational and Moral Philosophy.]
If Thomasius was the leader of those popular philosophers who, unconcerned about systematic continuity, discussed every question separately before the tribunal of common sense, and found in their lack of allegiance to any philosophical sect a sufficient guarantee of the unprejudicedness and impartiality of their reflections, Count Walter von Tschirnhausen (1651-1708; Medecina Mentis sive Artis Inveniendi Praecepta Generalia, 1687), a friend of Spinoza and Leibnitz, became the prototype of another group of the philosophers of the Illumination. This group favored eclecticism of a more scientific kind, by starting from considerations of method and seeking to overcome the antithesis between rationalism and empiricism. While fully persuaded of the validity and necessity of the mathematical method in philosophical investigations, as well as elsewhere, Tschirnhausen still holds it indispensable that the deductions, on the one hand, start from empirical facts, and, on the other, that they be confirmed by experiments. Inner experience gives us four primal facts, of which the chief is the certainty of self-consciousness. The second, that many things affect us agreeably and many disagreeably, is the basis of morals; the third, that some things are comprehensible to us and others not, the basis of logic; the fourth, that through the senses we passively receive impressions from without, the basis of the empirical sciences, in particular, of physics. Consequently consciousness, will, understanding, and sensuous representation (imaginatio), together with corporeality, are our fundamental concepts. Not perception (perceptio), but conception (conceptio) alone gives science; that which we can "conceive" is true; the understanding as such cannot err, but undoubtedly the imagination can lead us to confuse the merely perceived with that which is conceived. The method of science is geometrical demonstration, which starts from (genetic) definitions, and from their analysis obtains axioms, from their combination, theorems. That which is thus proved a priori must, as already remarked, be confirmed a posteriori. The highest of all sciences is natural philosophy, since it considers not sense-objects only, not (like mathematics) the objects of reason only, but the actual itself in its true character. Hence it is the divine science, while the human sciences busy themselves only with our ideas or the relations of things to us.
%2. Christian Wolff.%
Christian Wolff was born at Breslau in 1679, studied theology at Jena, and in addition mathematics and philosophy, habilitated at Leipsic in 1703, and obtained, through the instrumentality of Leibnitz, a professorship of mathematics at Halle, in 1706. His lectures, which soon extended themselves over all philosophical disciplines, met with great success. This popularity, as well as the rationalistic tendency of his thinking, aroused the disfavor of the pietists, Francke and Lange, who succeeded, in 1723, in securing from King Frederick William I. his removal from his chair and his expulsion from the kingdom. Finding a refuge in Marburg, he was called back to Halle by Frederick the Great a short time after the latter's ascension of the throne. Here he taught and wrote zealously until his death in 1754. In his lectures, as well as in half of his writings,[1] he followed the example of Thomasius in using the German language, which he prepared in a most praiseworthy manner for the expression of philosophical ideas and furnished with a large part of the technical terms current to-day. Thus the terms Verhältniss (relation), Vorstellung (representation, idea), Bewusstsein (consciousness), stetig (continuus), come from Wolff, as well as the distinction between Kraft (power) and Vermögen (faculty), and between Grund (ground) and Ursache (cause),[2] Another great service consisted in the reduction of the philosophy of Leibnitz to a systematic form, by which he secured a dissemination for it which otherwise it would scarcely have obtained. But he did not possess sufficient originality to contribute anything remarkable of his own, and it showed little self-knowledge when he became indignant at the designation Leibnitzio-Wolffian philosophy, which was first used by his pupil, Bilfinger. The alterations which he made in the doctrines of Leibnitz are far from being improvements, and the parts which he rejected are just the most characteristic and thoughtful of all. Such at least is the opinion of thinkers 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).]
[Footnote 2: Eucken, Geschichte der Terminologie^ pp. 133-134.]