being 'versed and studied' in all the facts appertaining to both sides of the matter, ends in the only alternative guess which remains open. And if that most troublesome individual, the 'plain man' of Locke, should say it seems at least opposed to common sense to suppose that there is anything in a burning candle or a rolling billiard-ball substantially the same as mind, the answer is that if he could look into my brain at this moment he would see nothing there but motion of molecules, or motion of masses; and apart from the accident of my being able to tell him so, his 'common sense' could never have divined that these motions in my brain are concerned in the genesis of my spoken thoughts.

It is obvious that from this hypothesis as to the substantial identity of mind and motion, two important questions arise; and I feel that some reference to these questions is in present circumstances forced upon me, because they have both been considered in precisely the same connexion by one of the most powerful intellects that was ever sent out into the world by this University. I mean the late Professor Clifford. As my intimate and valued friend, I desire to mention his name in this place with all the affection, as well as with all the admiration, to which I well know it is so fully entitled; and if I appear to mention him only in order to disagree with him, this is only because I know equally well that in his large and magnanimous thought differences of philosophical opinion were never felt to weaken the bonds of friendship.

In his well-known lecture on Body and Mind, Professor Clifford adopted the hypothesis of identity which we are now considering, and from it was led to the conclusion that if in the case of cerebral processes motion is one with mind, the same must be true of motion wherever it occurs; or, as he expressed it subsequently, the whole universe must be made of mind-stuff. But in his view, although matter in motion presents what may be termed the raw material of mind, it is only in the highly elaborated constitution of the human brain that this raw material is sufficiently wrought up to yield a self-conscious personality. Hence the dissolution of a human brain implies the dissolution of a human mind; and hence also the universe, although entirely composed of mind-stuff, is itself mindless. Now, all I have to say about these two deductions is this—they do not necessarily follow from the theory which is before us. In holding that the mind of man perishes with his body, and that above the mind of man there is no other, Clifford may have been right, or may have been wrong. I am not here to discuss at length any questions of such supreme importance. But I feel that I am here to insist upon the one point which is immediately connected with my subject; and this is, that whether or not Clifford was right in his conclusions, these conclusions certainly did not follow by way of any logical sequence from his premises. Because within the limits of human experience mind is only known as associated with brain, it clearly does not follow that mind cannot exist in any other mode. It does not even follow that any probability upon this matter can be thus established. The basis of analogy on which Clifford sought to rear an inference of cosmical extent, was restricted to the one instance of mind as known upon one planet; and, therefore, it is hard to imagine a more precarious use of that precarious method which is called by logicians simple enumeration. Indeed, even for what it is worth, the inference may be pointed with quite as much effect in precisely the opposite direction. For we have seen how little it is that we understand of the one mode in which we certainly know that mind does exist; and if from this little we feel impelled to conclude that there is a mode of mind which is not restricted to brain, but co-extensive with motion, is consubstantial and co-eternal with all that was, and is, and is to come; have we not at least a suggestion, that high as the heavens are above the earth, so high above our thoughts may be the thoughts of such a mind as this? I offer no opinion upon the question whether the general order of Nature does not require some one explanatory cause; nor upon the question whether the mind of man itself does not point to something kindred in the self-existing origin of things. I am not concerned to argue any point upon which I feel that opinions may legitimately differ. I am only concerned to show that, in so far as any deductions can be drawn from the theory which is before us, they make at least as much against as in favour of the cosmical conclusions arrived at by Clifford.

On February 17, in the year 1600, when the streets of Rome were thronged with pilgrims from all the quarters of Christendom, while no less than fifty cardinals were congregated for the Jubilee; into the densely crowded Campo di Fiori a man was led to the stake, where, 'silent and self-sustained,' before the eyes of all nations, he perished in the flames. That death was the death of a martyr: it was met voluntarily in attestation of truth. But most noble of all the noble army to which he belonged, the name of that man is written large in history, as the name of one who had fortitude to die, not in the cause of religious belief, but in that of scientific conviction. For why did Bruno suffer? He suffered, as we all know, because he refused to recant his persuasion of the truth of the Copernican theory. Why, then, do I adduce the name of Bruno at the close of this lecture? I do so because, as far as I have been able to ascertain, he was the first clearly to enunciate the monistic theory of things to which the consideration of my subject has conducted us. This theory—or that as to the substantial identity of mind and motion—was afterwards espoused, in different guises, by sundry other writers; but to Bruno belongs the merit of its original publication, and it was partly for his adherence to this publication that he died. To this day Bruno is ordinarily termed a pantheist, and his theory, which in the light of much fuller knowledge I am advocating, Pantheism. I do not care to consider a difference of terms, where the only distinction resides in so unintelligible an idea as that of the creation of substance. It is more to the purpose to observe that in the mind of its first originator—and this a mind which was sufficiently clear in its thought to die for its perception of astronomical truth—the theory of Pantheism was but a sublime extension of the then contracted views of Theism. And I think that we of to-day, when we look to the teaching of this martyr of science, will find that in his theory alone do we meet with what I may term a philosophically adequate conception of Deity. If the advance of natural science is now steadily leading us to the conclusion that there is no motion without mind, must we not see how the independent conclusion of mental science is thus independently confirmed—the conclusion, I mean, that there is no being without knowing? To me, at least, it does appear that the time has come when we may begin, as it were in a dawning light, to see that the study of Nature and the study of Mind are meeting upon this greatest of possible truths. And if this is the case—if there is no motion without mind, no being without knowing—shall we infer, with Clifford, that universal being is mindless, or answer with a dogmatic negative that most stupendous of questions—Is there knowledge with the Most High? If there is no motion without mind, no being without knowing, may we not rather infer, with Bruno, that it is in the medium of mind, and in the medium of knowledge, we live, and move, and have our being?

This, I think, is the direction in which the inference points, if we are careful to set