ether, air, and spirit as principles of explanation); the science of duty (which, as metaphysics, treats of duties toward God, as natural law, of duties to our neighbor, and deduces both from the primary duty of obedience to the will of God); and the science of the good (in which Ruediger follows the treatise of the Spaniard, Gracian, on practical wisdom).  Crusius agrees with Ruediger that mathematics is the science of the possible, and philosophy the science of the actual, and that the latter, instead of imitating to its own disadvantage the deductive-analytical method of geometry, must, with the aid of experience and with attention to the probability of its conclusions, rise to the highest principles synthetically.  Besides its deduction the determinism of the Wolffian philosophy gave offense, for it was believed to endanger morals, justice, and religion.  The will, the special fundamental power of the soul (consisting of the impulses to perfection, love, and knowledge), is far from being determined by ideas; it is rather they which depend on the will.  The application of the principle of sufficient reason, which is wrongly held to admit of no exception, must be restricted in favor of freedom.  For the rest, we may note concerning Crusius that he derives the principle of sufficient reason (everything which is now, and before was not, has a cause) and the principle of contingency from the principles of contradiction, inseparability, and incompatibility, and these latter from the principle of conceivability; that he rejects the ontological argument, and makes the ground of obligation in morality consist in obedience toward God, and its content in perfection.  Among the other opponents of the Wolffian philosophy, we may mention the theologian Budde(us)[3] (Institutiones Philosophiae Eclecticae, 1705); Darjes (who taught in Jena and Frankfort-on-the-Oder; The Way to Truth, 1755); and Crousaz (1744).

[Footnote 1:  Ruediger:  Disputatio de eo quod Omnes Idea Oriantur a Sensione, 1704; Philosophia Synthetica, 1707; Physica Divina, 1716; Philosophia Pragmatica, 1723.]

[Footnote 2:  Crusius:  De Usu et Limitibus Principii Rationis, 1743; Directions how to Live a Rational Life (theory of the will and of ethics), 1744; A Sketch of the Necessary Truths of Reason, 1745; Way to the Certainty and Trustworthiness of Human Knowledge, 1747.]

[Footnote 3:  J.J.  Brucker (Historia Critica Philosophiae, 5 vols., 1742-44; 2d ed., 6 vols., 1766-67) was a pupil of Budde.]

%3.  The Illumination as Scientific and as Popular Philosophy.%