Doubtless, from analogy, there is a presumption against the hypothesis that the same entity should exist in more than one mode at the same time; but clearly in this case we are quite unable to estimate the value of this presumption. Consequently, even assuming a causal connection between Matter and Human Mind, if there is any, the slightest, indications supplied by any other facts of experience pointing to the existence of a Divine Mind, such indications should be allowed as much argumentative weight as they would have had in the absence of the presumption we are considering. Hence Professor Clifford's conclusion cannot be regarded as valid until all the other arguments in favour of Theism have been separately refuted. Doubtless Professor Clifford will be the first to recognise the cogency of this criticism--if indeed it has not already occurred to him; for as I know that he is much too clear a thinker not to perceive the validity of these considerations, I am willing to believe that the substance of them was omitted from his essay merely for the sake of brevity; but, for the sake of less thoughtful persons, I have deemed it desirable to state thus clearly that the problem of Theism cannot be solved on grounds of Materialism alone. [This note was written before I had the advantage of Professor Clifford's acquaintance, but now I leave it, as I leave all other parts of this essay--viz., as it was originally written.--1878.] [8] To avoid burdening the text, I have omitted another criticism which may be made on Locke's argument. "Triangle" is a word by which we designate a certain figure, one of the properties of which is that the sum of its angles is equal to two right angles. In other words, any figure which does not exhibit this property is not that figure which we designate a triangle. Hence, when Locke says he cannot conceive of a triangle which does not present this property, it may be answered that his inability arises merely from the fact that any figure which fails to present this property is not a figure to which the term "triangle" can apply. Thus viewed, however, the illustration would obviously be absurd, for the same reason that the question of the clown is absurd, "Can you think of a horse that is just like a cow?" What Locke evidently means is, that we cannot conceive of any geometrical figure which presents all the other properties of a triangle without also presenting the property in question. Now, even admitting, with Locke, that it is as inconceivable that the entity known to us as Matter should possess the property of causing thought as it is that the figure which we term a triangle should posses the property of containing more than two right angles, still it remains, for the purposes of Locke's supposed theistic demonstration, to prove that it is an inconceivable for the entity which we call Mind _not_ to be due to another Mind, as it is for a triangle _not_ to contain, other than two right angles. But, further, even if it