G4 Baron Cuvicr's Lectures on the Natural Sciences. 



We now come to the part which more especially requires our 

 attention, the books which treat of the Physical Sciences. These 

 are numerous and varied ; there being, 1st, Eight books on pliy- 

 sics, properly so called ; four books on meteorology, in which 

 mention is also made of mineralogy ; one book o« colours ; 2dly, 

 Two books on the generation and the corruption of bodies, that 

 is to say, on the motions of decomposition and recomposition of 

 organised bodies ; ten on the history of animals, four on their 

 parts, one on their means of jjrogression, two on their genera- 

 tion, and various treatises on zoaking and sleeping. 



In all these works, Aristotle follows the same course as in his 

 poetics, ethics and politics ; that is, he lays down no rule a priori, 

 but deduces them all from the observation of particular facts,^ 

 and from their comparison. This method, besides, is only the 

 application of his theory respecting the origin of general ideas, 

 a theory which is the opposite of Plato's. That philosopher, 

 as we mentioned, in analysing his Tlmeeus, admitted that gene- 

 ral ideas exist by themselves, and maintained that they are in- 

 nate in man, that is to say, that his soul possessed them when it 

 was united to the divinity, and that when it recovers them, it is 

 by a true reminiscence. The evident consequence of this sys- 

 tem is to condemn the senses to inactivity, in order to favour 

 by contemplation the return of the mind towards its original 

 state. Aristotle justly opposes this doctrine. With him there 

 are no innate ideas. If the divinity has in itself all the general 

 ideas, it is because this belongs to its nature ; but, as to man, 

 he can only acquire them by means of abstraction, and, as no- 

 thing is found in his mind which has not fii'st passed through 

 his senses, all his knowledge necessarily takes its source in ob- 

 servation and experiment. From the single fact of having laid 

 down this principle in logic, there results a peculiar character 

 which his whole philosophy possesses, and a mode of proceeding 

 which is always the same in the moral sciences and in the physi- 

 cal sciences. When, for example, he has to speak on politics, 

 in place of first creating to himself an ideal republic, which 

 serves him as a type, a term of comparison for judging of the 

 goodness of the different existing governments, he begins witli 

 bringing togetlier a great number of constitutions, compares 

 them with each other, examines their influence upon die nations 



