98 FOL'KTH REPORT— 1834. 



of man, are particularly valuable. These faculties he connected 

 essentially with the organic body in which they are observed, and 

 referred them to a principle entirely different from what was then 

 considered elementarymatter, which was the cause of all the phae- 

 nomena observed in living bodies, and which controlled the quali- 

 ties of matter to its own destined purposes. On observing the 

 modes in which this principle manifests itself, he distinguished 

 them logically as faculties : the nutritive, the sensitive, the cogi- 

 tative, the motive. He then reasons on these logical distinctions 

 as if they were real independent existences ; and inquires whether 

 they may not exist in different and in the same bodies as such. 

 His conclusion is, that three of these faculties are faculties of one 

 and the same real existence, wherever they are observed ; but that 

 the fourth, the cogitative faculty, or rational soul, has a real and 

 independent existence. Thus he defined living bodies to be those 

 which contain within themselves the cause of their own motion. 

 But, far from supposing, as others have done, that this cause of 

 motion can move itself, he expressly states that the fundamental 

 causes of its motions are to be found elsewhere — in a supreme 

 animating principle, <^i;o-»j ; and asserted it to be the object of phi- 

 losophy to ascertain them. These delegated powers, he contends, 

 are four, — the material, the formal, the moving, the final causes. 

 The imknown cause of volition and the mental faculties he di- 

 stinguished as t\\eratio7ial soul; theunknown cause that produces 

 and sustains the body, as the organic instrument of the former 

 to effect its manifestations, he called the sentient soul*. Thus, 

 primary matter (uAij TrpuiTYj, an abstraction,) is utterly devoid of 

 properties ; it receives from ej'Soj all the shapes and powers 

 which it possesses : and so are formed the various bodies observ- 

 able in the universe with all their allotted qualities and energies. 



If we reflect on this theory of Aristotle, and divest it of its 

 scholastic form, we shall find that its generalizations do not very 

 materially differ from those which have, after strict observation 

 in modern times, been presumed to be the most just, and are now 

 the axioms of physiological science : viz. peculiar vital properties 

 inherent in peculiar material textures : — a cause of living motions 

 operating, by means of these textures, according to fixed laws : 

 and phaenomena so remarkably distinguished as to lead to their 

 (iivision into those of animal and of organic life, and indicative of 

 powers directed to a pui'pose which, in the first instance, is the 

 preservation of the body in which they are manifested. 



The Alexandrian school, founded by the Ptolemies, can scarcely 

 be considered as having made an adequate scientific return. What 



• Barclay On Life and Organization. 



