make it such a Creature as it is."[16] The seminal atoms come from all
parts of the body, the spiritual atoms from the male, and the material
atoms from the female. The atoms of Democritus are thus transmuted into
the "substantial forms" and endowed either with the efficient cause of
Aristotle or, permitted to remain material, with Aristotle's material
cause. According to Highmore, the atoms are circulated in the blood,
which is a "tincture extracted from those things we eat," and these
various atoms retain their formal identity despite corruption. The
testicles abstract some spiritual atoms belonging to each part and, "As
the parts belonging to every particle of the Eye, the Ear, the Heart,
the Liver, etc. which should in nutrition, have been added ... to every
one of these parts, are compendiously, and exactly extracted from the
blood, passing through the body of the Testicles." Being here "cohobated
and reposited in a tenacious matter," the particles finally pass out of
the testes.[17] A similar extraction of the female seed occurs in the
ovaries. The female seed

...containing the same particles, but cruder and lesse digested,
from a cruder matter, by lesse perfect Organs, is left more
terrene, furnished with more material parts; which being united in
the womb, with the spiritual particles of the masculine seed;
everyone being rightly, according to his proper place, disposed and
ordered with the other; fixes and conjoynes those spiritual Atomes,
that they still afterwards remain in that posture they are placed
in.[18]

The theories of development promulgated by Digby and Highmore reveal the
chief formulations of mechanistic rationalism, more or less free of
empiricism, that were emerging as the vitalism of the sixteenth and
seventeenth centuries waned. There was little new in these theories:
both Digby's and Highmore's theories included different combinations of
elements of ancient lineage. Digby's concept was essentially free of
vitalistic coloring; akin to the embryological efforts of Descartes in
its virtual independence from observations of the developing embryo, it
was similarly vulnerable to Voltaire's criticism of Descartes, that he
sought to interpret, rather than study, Nature. This criticism is not so
applicable to Highmore, whose theory of development is more vitalistic
than Digby's, and is more akin to the concepts developed by Gassendi
than those of Descartes.