cing or resisting motion. By inertia, I mean the incapacity to originate force or motion, or that quality which causes matter, if set in motion without other resistance than itself can supply, to keep on moving forever; or, if left at rest without other force than its own, to remain at rest forever. Materialism, hylozoism, and Tyndall's definition of matter, cannot justify themselves, unless it be proved that inertia is not a property of matter. Every student of this theme knows, and in this presence it is unnecessary for me to state, what the proofs are that matter cannot move itself. They are far more superabundant and crucial than even those which support the belief in the existence of gravitation. Newton himself did not regard attraction as an essential property of matter; and it was long a debate whether his great generalization should be named the theory of attraction, or the theory of propulsion. If the established definition of matter, and the consequent proof of the spiritual origin of all force, or of the Divine immanence in natural law, are not to be disestablished until that late day when the proof that inertia is not a property of matter, that is, that matter can move itself, can be put into the form of a syllogism, then the yoke of Socrates, Aristotle, and Plato, of which Tyndall complains, that, after twenty centuries, it is yet unbroken, is likely to continue to be what it now is, one of the best examples in history of the survival of the fittest.

2. The established definition of matter rests on facts verifiable by experience; Tyndall's, confessedly,

is demanded and supported only by the tendencies of an improved theory of evolution.

"Those who hold the doctrine of evolution," says Tyndall himself, "are by no means ignorant of the uncertainty of their data, and they yield no more to it than a provisional assent. They regard the nebular hypothesis as probable; and, in the utter absence of any evidence to prove the act illegal, they extend the method of nature from the present into the past, and accept as probable the unbroken sequence of development from the nebula to the present time" (Fragments of Science, p. 166).

In his Belfast Address, Tyndall says, "The strength of the doctrine of evolution consists not in an experimental demonstration, but in its general harmony with the method of Nature as hitherto known." But his definition of matter rests only on this theory, which, as he admits, is not verified by experiment; while the accepted definition of matter is so verified. It is notoriously to experiment, and to ages of experiment, and to necessary belief itself, that the accepted definition appeals; it is to the exigencies of an unverified, and experimentally unverifiable theory, that Tyndall appeals.

3. According to the doctrines of analogy and uniformity, on which Tyndall relies, matter must be supposed to be inert where we cannot experiment on it, since it is where we can.

4. Tyndall admits that the manner of the connection between matter and mind is unthinkable, and that, "if we try to comprehend that connection, we

sail in a vacuum." His own definition, therefore, involves propositions which are unthinkable. They must have been reached by sailing through a vacuum, and can be proved only by a similarly adventurous voyage.

Pertinent exceedingly to the criticism of his definition of matter are Tyndall's famous admissions that "molecular groupings and molecular motions explain nothing;" that "the passage from the physics of the brain to the corresponding facts of consciousness is unthinkable ;" and that, if love were known to be associated with a right-handed spiral motion of the molecules of the brain, and hate with a left-handed, we should remain as ignorant as before as to the cause of the motion" (Fragments of Science, pp. 120, 121). If the connection between matter and thought in the brain is so obscure, that neither Tyndall, nor Spencer, nor Bain, calls it the connection of cause and effect, but only that of antecedent and consequent, how can the connection between matter and thought in the nebula be so clear, that Tyndall can discern in it, at that distance, "the promise and potency of every form and quality of life"? How is it that the relations of matter and mind are unthinkable as they exist in the brain, and thinkable as they exist in the nebula? How is it that the nervous vibrations and the corresponding events of consciousness are, as Tyndall believes them to be, simply consecutive, or correlative, a case of "parallelism without contact," while the matter of the

universe, and the life and thought existing in the

.

universe, are so far from being a case of parallelism without contact, that the "potency" of the latter is all in the former?

5. The established definition of matter will, and Tyndall's will not, bear Tyndall's own test of clear mental presentation.

Bishop Butler shows this well enough, even when Tyndall himself, in the Belfast Address, composes the Bishop's argument. Undoubtedly Tyndall has not laid too much emphasis on the famous German saying, "The true is the clear." But his definition, contemplated with all patience and candor, is clear in neither its affirmations nor its negations; while the established is capable of a coherent presentation in both these respects. So far, indeed, is the Belfast Address from knowing its own opinion, that in one place it says the very existence of matter as a reality outside of the mind is "not a fact, but an inference," thus implying that Tyndall is not sure but that Fichte's idealism may be the truth.

6. The established definition is justified, and Tyndall's is not, by the irresistible testimony of consciousness that the will has efficiency as a cause.

Dr. W. B. Carpenter, a far better physiologist than Tyndall, and whose work on "Mental Physiology," just issued, is, always excepting Lotze's "Mikrokosmus," the best discussion produced in modern times of the connection between body and mind, analyzes elaborately all the latest facts, including Professor Ferrier's proof of the localization of functions in the brain; but he saves himself, as Lotze

does, from fatalism, materialism, hylozoism, and from that definition of matter which Tyndall adopts. He affirms a very broad and sometimes startling doctrine of unconscious cerebration, but finds in the properties of the nervous mechanism no explanation whatever of our consciousness, that, by acts of will, we can originate physical movements, and control the direction of courses of thought. The central part of Tyndall's errors is to be found in his shy treatment of this necessary belief. There results from this shyness his insufficiently clear idea of what he means by causation. Almost while Tyndall was speaking before the British Association at Belfast on atoms, M. Wurtz, president of the French Association, was discussing before that body the same theme, and closing an opening address with no unscientific indistinctness as to what cause signifies. "It is in vain," he said, "that science has revealed to it the structure of the world and the order of all the phenomena: it wishes to mount higher; and in the conviction that things have not in themselves their own raison d'être, their support and their origin, it is led to subject them to a first cause, unique and universal God" (Address republished in "Nature," Aug. 27, 1874).

So much does Tyndall's Address lean on Professor Draper's book on "The Intellectual Development of Europe," that it is a witticism of the London press, that the discourse is rather vapory when stripped of its drapery; but Draper himself, in an elaborate chapter of his "Human Physiology" (pp. 283-290),