2 
of logic, in the very commencement of his work, 
Teo Zadv, “ have parts which are neither specifically 
the same with those of other animals, nor generically 
the same, with mere difference of quantity, excess 
or defect, but are merely accordant, or the same in 
the relation of analogy: as the bone is by analogy 
the same with the cartilaginous spine of the acan- 
thus, (probably the thornback,) the nail with the 
hoof, (as of a horse,) the hand with the claw, (as of 
a bird,) the scale with the feather: for the feather 
in the bird agrees analogically in its relation, though 
not in appearance, with the scale of the fish.” 
An author, whose writings afford the best key 
and clue to Aristotle, to logic, and to nature, thus 
defines analogy: ‘ Strictly speaking, analogy ought 
to be distinguished from direct resemblance, with 
which it is often confounded, in the language of even 
eminent writers, (especially on chemistry and na- 
tural history,) in the present day. Analogy being 
‘a resemblance of ratios,’ Acywy 6jodrys, (Aristotle, ) 
that should strictly be called an argument from ana- 
logy in which the two things, viz. the one from 
which, and the one fo which we argue, are not in 
themselves alike, but stand in similar relations to 
some other things: or, in other words, when the com- 
mon genus, under which they both fall, consists in a 
relation. Thus an egg and a seed are not in them- 
selves alike, but bear a like relation’ to the parent 
bird and to her future nestling, on the one hand, 
and to the old and young plant, on the other, re- 
spectively. In this kind of argument one error is 
