of the real nature of genius, that is to say, of that mental endowment which alone can produce genuine works of art. But this necessitates a brief explanation of madness itself.(50) A clear and complete insight into the nature of madness, a correct and distinct conception of what constitutes the difference between the sane and the insane, has, as far as I know, not as yet been found. Neither reason nor understanding can be denied to madmen, for they talk and understand, and often draw very accurate conclusions; they also, as a rule, perceive what is present quite correctly, and apprehend the connection between cause and effect. Visions, like the phantasies of delirium, are no ordinary symptom of madness: delirium falsifies perception, madness the thoughts. For the most part, madmen do not err in the knowledge of what is immediately _present_; their raving always relates to what is _absent_ and _past_, and only through these to their connection with what is present. Therefore it seems to me that their malady specially concerns the memory; not indeed that memory fails them entirely, for many of them know a great deal by heart, and sometimes recognise persons whom they have not seen for a long time; but rather that the thread of memory is broken, the continuity of its connection destroyed, and no uniformly connected recollection of the past is possible. Particular scenes of the past are known correctly, just like the particular present; but there are gaps in their recollection which they fill up with fictions, and these are either always the same, in which case they become fixed ideas, and the madness that results is called monomania or melancholy; or they are always different, momentary fancies, and then it is called folly, _fatuitas_. This is why it is so difficult to find out their former life from lunatics when they enter an asylum. The true and the false are always mixed up in their memory. Although the immediate present is correctly known, it becomes falsified through its fictitious connection with an imaginary past; they therefore regard themselves and others as identical with persons who exist only in their imaginary past; they do not recognise some of their acquaintances at all, and thus while they perceive correctly what is actually present, they have only false conceptions of its relations to what is absent. If the madness reaches a high degree, there is complete absence of memory, so that the madman is quite incapable of any reference to what is absent or past, and is only determined by the caprice of the moment in connection with the fictions which, in his mind, fill the past. In such a case, we are never for a moment safe from violence or murder, unless we constantly make the madman aware of the presence of superior force. The knowledge of the madman has this in common with that of the brute, both are confined to the present. What distinguishes them is that the brute has really no idea of the past