change?  Clearly a certain impetus imparted to the balls, and certain fixed laws under which that impetus operates.  The question is what laws and what impetus are these?  Are they the same or not the same, now the balls correspond to consciousness, as they were before, when the balls did not correspond to it?  One of two things must happen.  Either the balls go on moving by exactly the same laws and forces they have always moved by, and are in the grasp of the same invincible necessity, or else there is some new and disturbing force in the midst of them, with which we have to reckon.  But if consciousness is inseparable from matter, this cannot be.  Do the billiard-balls when so grouped as to represent consciousness generate some second motive power distinct from, at variance with, and often stronger than, the original impetus?  Clearly no scientific thinker can admit this.  To do so would be to undermine the entire fabric of science, to contradict what is its first axiom and its last conclusion.  If then the motion of our six billiard balls has anything, when it corresponds to consciousness, distinct in kind from what it always had, it can only derive this from one cause.  That cause is a second cue, tampering with the balls and interfering with them, or even more than this—­a second hand taking them up and arranging them arbitrarily in certain figures.

Science places the positive school on the horns of a dilemma.  The mind or spirit is either arranged entirely by the molecules it is connected with, and these molecules move with the same automatic necessity that the earth moves with; or else these molecules are, partially at least, arranged by the mind or spirit.  If we do not accept the former theory we must accept the latter:  there is no third course open to us.  If man is not an automaton, his consciousness is no mere function of any physical organ.  It is an alien and disturbing element.  Its impress on physical facts, its disturbance of physical laws, may be doubtless the only things through which we can perceive its existence; but it is as distinct from the things by which we can alone at present perceive it, as a hand unseen in the dark, that should arrest or change the course of a phosphorescent billiard-ball.  Once let us deny even in the most qualified way that the mind in the most absolute way is a material machine, an automaton, and in that denial we are affirming a second and immaterial universe, independent of the material, and obeying different laws.  But of this universe, if it exists, no natural proof can be given, because ex hypothesi it lies quite beyond the region of nature.

One theory then of man’s life is that it is a union of two orders of things; another, that it is single, and belongs to only one.  And of these theories—­opposite, and mutually exclusive, Dr. Tyndall, and modern positivism with him, says ’I reject neither.’[35]