PHYSIOLOGY OF LIFE. 41 



and essentially diverse. For as to abstract the idea of 

 kind from that of degrees, which are alone designated in 

 the language of common use, is the first and indispensable 

 step in philosophy, so are we the better enabled to form 

 a notion of the kind, the lower the degree and the simpler 

 the form is in which it appears to us. We study the com- 

 plex in the simple; and only from the intuition of the 

 lower can we safely proceed to the intellection of the 

 higher degrees. The only danger lies in the leaping from 

 low to high, with the neglect of the intervening gradations. 

 But the same error would introduce discord into the gamut, 

 et ab abusu contra usum non valet consequentia. That these 

 degrees will themselves bring forth secondary kinds suffi- 

 ciently distinct for all the purposes of science, and even 

 for common sense, will be seen in the course of this in- 

 quisition : for this is one proof of the essential vitality 

 of nature, that she does not ascend as links in a suspended 

 chain, but as the steps in a ladder ; or rather she at one 

 and the same time ascends as by a climax, and expands 

 as the concentric circles on the lake from the point to 

 which the stone in its fall had given the first impulse. 

 At all events, a contemptuous rejection of this mode of 

 reasoning would come with an ill grace from a medical 

 philosopher, who cannot combine any three phenomena 

 of health or of disease without the assumption of powers, 

 which he is compelled to deduce without being able to 

 demonstrate; nay, even of material substances as the 

 vehicles of these powers, which he can never expect to ex- 

 hibit before the senses. 



From the preceding it should appear, that the most 

 comprehensive formula to which life is reducible, would 



