e universe the spirits which
disturbed the calm of the philosopher.

There was only one field in which ancient science seemed to break away
from the fixed assumptions of its metaphysics and from the definitions
of natural objects which were the bases for their scientific inferences,
this was the field of astronomy in the period after Eudoxus. Up to and
including the theories of Eudoxus, physical and mathematical astronomy
went hand in hand. Eudoxus' nests of spheres within spheres hung on
different axes revolving in different uniform periods was the last
attempt of the mathematician philosopher to state the anomalies of the
heavens, and to account for the stations, the retrogressions, and
varying velocities of planetary bodies by a theory resolving all
phenomena of these bodies into motions of uniform velocities in perfect
circles, and also placing these phenomena within a physical theory
consistent with the prevailing conceptions of the science and philosophy
of the time. As a physicist Aristotle felt the necessity of introducing
further spheres between the nests of spheres assigned by Eudoxus to the
planetary bodies, spheres whose peculiar motions should correct the
tendency of the different groups of spheres to pass their motions on to
each other. Since the form of the orbits of heavenly bodies and their
velocities could not be considered to be the results of their masses and
of their relative positions with reference to one another; since it was
not possible to calculate the velocities and orbits from the physical
characters of the bodies, since in a word these physical characters did
not enter into the problem of calculating the positions of the bodies
nor offer explanations for the anomalies which the mathematical
astronomer had to explain, it was not strange that he disinterested
himself from the metaphysical celestial mechanics of his time and
concentrated his attention upon the geometrical hypotheses by means of
which he could hope to resolve into uniform revolutions in circular
orbits the anomalous motions of the planetary bodies. The introduction
of the epicycle with the deferent and the eccentric as working
hypotheses to solve the anomalies of the heavens is to be comprehended
largely in view of the isolation of the mathematical as distinguished
from the physical problem of astronomy. In no sense were these
conceptions working hypotheses of a celestial mechanics. They were the
only means of an age whose math