desires, although, and just because, he actually perceives nothing at all. To the weak-headed everything which is clearly, firmly defined, and which, therefore, has strictly but one meaning, is flat. To them everything is profound which has no meaning, and which, therefore, allows them to apply what meaning they please. To them mathematical analysis is flat; theology and metaphysics, deep. The study of Roman law is flat; the dream-book and the prophecies of Nostradamus are deep. The forms assumed by pouring molten lead on New Year’s Eve are the true symbols of their depth. The content of mystic thought is determined by the individual character and level of culture possessed by each degenerate and hysteric. For we should never forget that the morbidly-affected or exhausted brain is only the soil which receives the seed sown by nurture, education, impressions and experience of life, etc. The seed-grains do not originate in the soil; they only receive in and through it their special irregularities of development, their deformities, and crazy offshoots. The naturalist who loses the faculty of attention becomes the so-called ‘Natural Philosopher,’ or the discoverer of a fourth dimension in space, like the unfortunate Zöllner. A rough, ignorant person from the low ranks of the people falls into the wildest superstition. The mystic, nurtured in religion and nourished with dogma, refers his shadowy impressions to his beliefs, and interprets them as revelations of the nature of the Trinity, or of the condition of existence before birth or after death. The technologist who has fallen into mysticism worries over impossible inventions, believes himself to be on the track of the solution of the problem of a _perpetuum mobile_, devises communication between earth and stars, shafts to the glowing core of the earth, and what not. The astronomer becomes an astrologist, the chemist an alchemist and a seeker after the philosopher’s stone; the mathematician labours to square the circle, or to invent a system in which the notion of progress is expressed by a process of integration, the war of 1870 by an equation, and so on.