It is, I hope, unnecessary to observe that, so far as the ultimate mystery of existence is concerned, any and every theory of things is equally entitled to the inexplicable fact that something is; and that any endeavour on the part of the votaries of one theory to shift from themselves to the votaries of another theory the _onus_ of explaining the necessarily inexplicable, is an instance of irrationality which borders on the ludicrous. Sec. 4. Another argument, or semblance of an argument, is the very prevalent one, "Our heart requires a God; therefore it is probable that there is a God:" as though such a subjective necessity, even if made out, could ever prove an objective existence.[1] Sec. 5. If it is said that the theistic aspirations of the human heart, by the mere fact of their presence, point to the existence of a God as to their explanatory cause, I answer that the argument would only be valid after the possibility of any more proximate causes having been in action has been excluded--else the theistic explanation violates the fundamental rule of science, the Law of Parcimony, or the law which forbids us to assume the action of more remote causes where more proximate ones are found sufficient to explain the effects. Consequently, the validity of the argument now under consideration is inversely proportional to the number of possibilities there are of the aspirations in question being due to the agency of physical causes; and forasmuch as our ignorance of psychological causation is well-nigh total, the Law of Parcimony forbids us to allow any determinate degree of logical value to the present argument. In other words, we must not use the absence of knowledge as equivalent to its presence--must not argue from our ignorance of psychological possibilities, as though this ignorance were knowledge of corresponding impossibilities. The burden of proof thus lies on the side of Theism, and from the nature of the case this burden cannot be discharged until the science of psychology shall have been fully perfected. I may add that, for my own part, I cannot help feeling that, even in the present embryonic condition of this science, we are not without some indications of the manner in which the aspirations in question arose; but even were this not so, the above considerations prove that the argument before us is invalid. If it is retorted that the fact of these aspirations having had _proximate_ causes to account for their origin, even if made out, would not negative the inference of these being due to a Deity as to their _ultimate_ cause; I answer that this is not to use the argument from the presence of these aspirations; it is merely to beg the question as to the being of a God.