Noblest of all are those whose blood is hot, and at the
same time thin and clear. For such are suited alike for the
development of courage and of intelligence. Accordingly, the upper
parts are superior in these respects to the lower, the male superior
to the female, and the right side to the left. As with the blood so
also with the other parts, homogeneous and heterogeneous alike. For
here also such variations as occur must be held either to be related
to the essential constitution and mode of life of the several animals,
or, in other cases, to be merely matters of slightly better or
slightly worse. Two animals, for instance, may have eyes. But in one
these eyes may be of fluid consistency, while in the other they are
hard; and in one there may be eyelids, in the other no such
appendages. In such a case, the fluid consistency and the presence
of eyelids, which are intended to add to the accuracy of vision, are
differences of degree. As to why all animals must of necessity have
blood or something of a similar character, and what the nature of
blood may be, these are matters which can only be considered when we
have first discussed hot and cold. For the natural properties of
many substances are referable to these two elementary principles;
and it is a matter of frequent dispute what animals or what parts of
animals are hot and what cold.
Pages:
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52