apprehended by the Mind.

The Aristotelian view of Nature as an energetic process failed to
impress itself upon his successors. Greek Philosophy soon after
Aristotle's death decayed or was deprived of its early vigour, and the
doctrine which survived the wreck was essentially derived, however
imperfectly, from the Platonic theory.

Throughout the first fifteen hundred years of the Christian era this
doctrine undoubtedly dominated the course of speculation--a speculation
of which much is now forgotten and almost as much was certainly barren
and unfruitful, but of which we would entertain a very mistaken notion
if we were to imagine that it was not often pursued with great subtlety
and acumen.

One natural result of the fact that such a principle dominated human
thought was the prevalence of a belief that the explanation of Nature
and natural processes could be derived from the cognitive faculty
itself. Our cognition of our immediate surroundings was doubtless
continuously corrected by immediate practical tests. But the science of
a more extended view of Nature was vitiated by this false principle and
in consequence for many centuries our whole Knowledge of Nature remained
unprogressive and unfruitful.

_Causa aequat effectum_, Nature abhors a vacuum, are examples of the
maxims derived or supposed to be derived from the necessities of our
Reason, and by the aid of which it was vainly hoped to attain a
knowledge of Nature and natural laws.

The principle was in itself unsound.

The necessary laws of our rational faculty could discover to us only the
essentials of that faculty itself.

The maxims by which it was sought to constitute _a priori_ a scheme of
natural laws could not justly claim descent from the necessities of
Thought. Had the Schoolmen formed a true conception of the nature of
Knowledge they would never have imagined that any necessity of Thought
obliged them to believe that a 10 lb. weight would fall to the ground
more rapidly than a 1 lb. weight. Equally true is it that their
scientific principles had not been derived from any study of the action
of natural law. They were unacknowledged intellectual orphans.

The movement associated with the names of Galileo, Bruno, Bacon, Kepler,
and Newton owed its origin and its success to the abandonment of this
vicious principle. So far as Nature was concerned, the Mind was regarded
as a _tabula rasa_, and the physician set himself to ascertain the laws
of nat