The transition is startling from this conception of Philosopher as a very high kind of man of the world, to the definition of Philosophy as "the science of possibles qua possibles." Diderot's own reflection comes back to us, _Combien cette maudite metaphysique fait des fous!_[183] We are abruptly plunged from a Baconian into a Leibnitzian atmosphere. We should naturally have expected some such account of Philosophy as that it begins with a limitation of the questions to which men can hope for an answer, and ends in an ordered arrangement of the principles of knowledge, with ultimate reference to the conditions of morals and the structure of civil societies. We should naturally have expected to find, what indeed we do find, that the characteristic of the philosopher is to "admit nothing without proof, never to acquiesce in illusory notions; to draw rigorously the dividing lines of the certain, the probable, the doubtful; above all things never to pay himself with mere words." But then these wholesome prescriptions come in an article whose definitions and distribution of philosophy are simply a reproduction from Christian Wolff, and the methods and dialect of Wolff are as essentially alien from the positive spirit of the Encyclopaedia as they were from the mystic spirit of Jacobi. Wolff's place in the philosophical succession of German speculation (1679-1754) is between Leibnitz and Kant, and until Kant came his system was dominant in the country of metaphysics.[184] It is from Wolff that Diderot borrows and throws unassimilated into the pages of the Encyclopaedia propositions so fundamentally incongruous as this, that "among all possibles there must of necessity be a Being subsisting by himself; otherwise there would be possible things, of the possibility of which no account could be given, an assertion that could never be made." It is a curious thing, and it illustrates again the strangely miscellaneous quality of Diderot's compilation, that the very article which begins by this incorporation of the author of a philosophical system expounded in a score of quartos, ends by a vigorous denunciation of the introduction of the systematic spirit into philosophy.