224 Notices respecting New Books. 
nately ; observations always precise, exact, important, and which 
have only for their object facts and their immediate relations ; 
reasoning often uncertain or hazardous, and to which there are 
no limits ; the one a sure guide, which constantly leads to true 
but confined results ; the other, which is faithful to genius alone, 
and from which spring the highest virtues and the greatest errors. 
It is the submission of reasoning to observation which ‘forms 
the characteristic of modern science. A law is regarded as no 
further obligatory than when it is supported not only by facts 
but by an assemblage of facts, the analogy between which may 
be positive, and which no prejudice can have misinterpreted. 
Here, however, arises a difficulty.—In what.does this resem- 
blance consist? Nature, infinite in its powers, is equally infinite 
in its productions ; it varies them without measure: while obser- 
vation only comprehends individuals ; and hence results the de- 
mand for generalization, for principle, and for system. It is thus 
that all sciences are under the necessity of mixing reasoning with 
observation, though in different degrees; and it is in the use 
which each is allowed to make of these two modes of investiga- 
tion, that their philosophy truly consists. 
The objects with which the sciences of observation are occu- 
pied, which are possessed of qualities the most various, and whose 
relations are most extended, are animals; and of all the divisions 
into which: the study of animals divides itself, comparative ana- 
tomy is beyond all doubt that in which reasoning is most indis- 
-pensable. 
-Until the present day, this important branch of natural science 
chad only admitted a very small number of general laws, Its pru- 
‘dent inductions. were never established but upon facts, whose evi- 
dent analogy does not leave any thing to doubt or uncertainty ; 
and new observations have still been the principal object of its 
researches—a conduct doubtless most wise in ascience so favour- 
able to the love of hypothesis, and where errors are so easy and so 
‘seducing. 
It is thus that, with the aid of those inductions, physiologists 
have been led to unite all the animals provided with an osseous 
frame or skeleton under the name of Vertebral; and according 
to the agreement of their different systems of organs to establish 
the subordination of their characters, and to class each in respect 
to the others in a methodical and natural manner ; to see auen- 
tire analogy between the hand of man, the foot of the horse, the 
-wing of the bird, the pectoral fin of fish, &c. From these facts 
joined to many others, they have ventured to conjecture, that in 
‘the creation of all vertebral animals nature has followed a general 
plan, which she has only modified in some points, in order to 
make a distinction of species ; and that she has only passed from 
one 
