Some of the most regrettable and injurious failings which disfigure and defame the character run through families, appearing in successive generations and seeming to be inherited. This theory of their perpetuation is well founded; and it has been adduced as conclusive evidence of the truth of the hypothesis that mind, and, of course, character, is the mere outcome of matter. The force of the argument obviously rests on the assumption that nothing more than, or outside, matter can be transmitted from parent to child; that a particular constitution of brain and nerve centres, a special arrangement or combination of the elements which compose the mind-organ, may be reproduced, and, if it is, a similarity of character will be entailed; but as for the independent existence of mind, or spirit, that is a pure figment of the imagination, which science will sooner or later drive beyond the pale of credulity, and to which, even now, only a few thinkers avowedly cling!
Let us examine this proposition at close quarters. It may be stated thus. All we know of mind is expressed, and understood, by physical agencies and in the formulæ of material force. Speech communicates thought, and we think in words. The faculty of forming and employing words is a brain function. If a particular region of the brain be injured or diseased, the power of using language, at least in speech, is _generally_ lost. The materialist argues from this and many similar facts that mind is the product of matter. He fails to perceive that the only warrantable deduction from his own data is that mind or spirit, call it what we will, _can only express itself_ through the brain as an instrument. As well deny the skill or independent existence of a musician because he can not play the full score of an opera on a flute, as infer the non-existence of a soul from the fact that man cannot perform intellectual work without the organ of thought—the brain!
The capacity of the instrument doubtless limits the expression, but it supplies no measure of the power or skill of the performer, except in so far as the use he makes of the instrument may be a bad one. This exception is of great significance, and there will be something more to say about it presently. Meantime it is evident that, while the range of brain-power determines the _manifestation_ of mind, it neither measures, nor affirms, nor disproves the independent existence of mind. The anatomist, the physiologist, and the chemist declare their inability to discover the traces of a soul in the physical organism. That no more proves the non-existence of a soul than the failure to recognize more than a certain number of planets at any stage in the history of astronomy demonstrated that there was nothing further to find.