Exactly _how_ all this can come about I shall now endeavour to show. Before any of the more complex and complicated disorders of the mind can be understood, it will be necessary for us to discuss very briefly the nature of the subconscious mind--since it is upon this that all modern researches have in a great measure rested--upon the improved understanding of its nature that many of these cures rest. It has long been known that there is a sort of mind in us, capable, at times, of performing complicated and intelligent actions without the co-operation or knowledge of the conscious mind. We see examples of this daily--in the absent-minded actions of certain individuals, in the dream life, in hypnotic trance, and in many of the cases of normal and peculiar mental action, of which numerous examples might be given, but which are so well known that it is hardly necessary at this late date to elaborate in detail. The idea has been so extensively employed by Hudson in his theory of "the subjective mind," and by others, that the general theory has pretty well saturated the public mind. Hudson's theory--otherwise open to many criticisms--is very lax, not to say erroneous, in its construction, and is not accepted today by any competent psychologist. Apart from the mysterious powers with which he endowed the "subjective" mind, he makes it now synonymous with the _whole_ of the subconscious life outside the field of immediate consciousness; now as equivalent merely to the hypnotic stratum; now to a dream-like self, etc., until the term has become so elastic that it means nothing intelligible but everything in general! As understood by the modern psychologist, the term "subconscious mind" must be defined far more accurately before we can proceed to use it as a working hypothesis. What, then, is understood by the subconscious mind? What part of us can perform conscious operations without our being conscious of them? How can we perform intelligent operations without intelligence? It all depends upon the meaning we give to our terms. We must begin by explaining just what is meant by the "subconscious mind"; then, perhaps, we can better understand its operations and aberrations.