“_Mutatis mutandis_, the above would seem to hold as truly about medicine as about politics. We cannot reason with our cells, for they know so much more” (of course I mean “about their own business”) “than we do, that they cannot understand us;—but though we cannot reason with them, we can find out what they have been most accustomed to, and what, therefore, they are most likely to expect; we can see that they get this as far as it is in our power to give it them, and may then generally leave the rest to them, only bearing in mind that they will rebel equally against too sudden a change of treatment and no change at all” (p. 305). Dr. Creighton insists chiefly on the importance of change, which—though I did not notice his saying so—he would doubtless see as a mode of cross-fertilisation, fraught in all respects with the same advantages as this, and requiring the same precautions against abuse; he would not, however, I am sure, deny that there could be no fertility of good results if too wide a cross were attempted, so that I may claim the weight of his authority as supporting both the theory of an unconscious memory in general, and the particular application of it to medicine which I had ventured to suggest. “Has the word ‘memory,’” he asks, “a real application to unconscious organic phenomena, or do we use it outside its ancient limits only in a figure of speech?” “If I had thought,” he continues later, “that unconscious memory was no more than a metaphor, and the detailed application of it to these various forms of disease merely allegorical, I should still have judged it not unprofitable to represent a somewhat hackneyed class of maladies in the light of a parable. None of our faculties is more familiar to us in its workings than the memory, and there is hardly any force or power in nature which every one knows so well as the force of habit. To say that a neurotic subject is like a person with a retentive memory, or that a diathesis gradually acquired is like an over-mastering habit, is at all events to make comparisons with things that we all understand. “For reasons given chiefly in the first chapter, I conclude that retentiveness, with reproduction, is a single undivided faculty throughout the whole of our life, whether mental or bodily, conscious or unconscious; and I claim the description of a certain class of maladies according to the phraseology of memory and habit as a real description and not a figurative.” (p. 2.) As a natural consequence of the foregoing he regards “alterative action” as “habit-breaking action.”