Notices respecting New Books. 431 



into natural history by Mr. Macleay and his disciples, to that which 

 has long been pursued in dynamics, astronomy, and other depart- 

 ments of general physics. This is a point on which we feel some 

 anxiety, for we are of opinion that Mr. Macleay's discoveries, and 

 they alone, have at length raised the study of Natural History to a 

 level with the higher Physics. And as the cultivators of the latter do 

 not as yet appear adequately to appreciate the dignity, as a branch of 

 inductive science, of Natural History, we are on tliat account also glad 

 to have this opportunity of drawing their attention to the subject, by 

 stating what we believe to be the correct view of it in this respect. 



The assembling of species into groups, then, according to the tota- 

 lity of the characters of every species, and the variation of those cha- 

 racters, and of the groups so established into greater groups, by the 

 same process, is, we conceive, precisely analogous to what Mr. Her- 

 schel, in his Preliminary Discourse on the Study of Natural Philosophy, 

 terms " the first stage of induction" that is, the discovery of proximate 

 causes, and laws of the lowest degree of generality, in physics. And 

 the investigation of the abstract principles of affinity and analogyj 

 of the true nature of what Mr. Macleay has called osculant groups ; of 

 the intimate quality of the affinity of transultation ; of that of the 

 process bv which, in the union of contiguous groups of a certain rank, 

 the relation of analogy insensibly becomes a relation of affinity, &c., 

 are as precisely analogous to the higher degrees of inductive genera- 

 lization, in physics. With the above, other considerations are con- 

 nected, which may throw some degree of light on the misconceptions 

 which have been broached on the subject we have already twice no- 

 ticed, the true claims of the Macleayan system to be that of nature, 

 and which are in a manner sneered at by Mr. Kennie, in his introduc- 

 tory page examined in p. 375—379. 



We will return to Mr. Macleay's illustration of the difference be- 

 tween an artificial system and that of nature, by allusion to a sup- 

 posed and to the real arrangement of the planets composing our solar 

 system. Pursuing this illustration, we affirm, that the discovery of 

 the natural system by the means adopted by Mr. Macleay and the 

 naturalists of his school, is closely analogous to, is as strictly induc- 

 tive, as truly logical, and claims as much the regard of every reflect- 

 ing mind, as, the discovery of the natural system of the planetary and 

 sidereal universe, by the means, appropriate to that sphere of re- 

 search, which have been adopted by astronomers and mathematicians. 

 For the further use of this illustration we will extend it ; we will re- 

 gard the natural system of the planets as being, not merely their ar- 

 rangement, as circulating around the sun, and the knowledge of it, 

 but as the assemblage of laws which govern their motions, and of 

 proximate or remote causes of their pheenomena. 



The natural system of the planets, taking that term in its lowest 

 acceptation, was, as is well known, discovered by Copernicus. But 

 his discovery, although complete in itself, although consisting of de- 

 monstrated truths, did not extend to the entire natural .system of these 

 bodies ; although the system promulgated was, in the proper sense of 

 the term, a natural one, yet much remained to be discovered of that 



system- 



