Introduction
What is common to these spirits is a strong feeling that in man's self-knowledge arises a sun which illuminates something beyond the incidental individual personality of the beholder. What Spinoza realized in the ethereal height of pure thought, that “the human soul has a sufficient knowledge of the eternal and infinite nature of God,” lived in them as immediate perception; and for them self-knowledge was the path by which this eternal and infinite nature was to be reached. It was clear to them that self-knowledge in its true form endows man with a new sense which opens to him a world that has the same relation to what can be attained without this sense as does the world of the physically sighted to that of the blind. It would not be easy to find a better description of the importance of this new sense than that given by J. G. Fichte in his Berlin lectures in the year 1813. “Imagine a world of people born blind, who therefore know only those objects and their conditions which exist through the sense of touch. Go among them and speak to them of colors and of the other conditions which exist only for sight through the medium of light. Either you will speak to them of nothing, and it will be better if they say so, for in this way you will soon notice your mistake, and, if you cannot open their eyes, will put an end to this fruitless talk.—Or for some reason they will want to give a meaning to your teaching; in this case they will only be able to understand it through what they know from touch: they will want to feel the light, the colors, and the other conditions of visibility; they will think that they feel them, will, within the realm of touch, make up something that they call color and deceive themselves with it. Then they will misunderstand, turn things around, and misinterpret.” Something similar may be said of that toward which the spirits under discussion strove. In self-knowledge they saw the opening up of a new sense. And in their opinion this sense leads to insights which do not exist for one who does not perceive in self-knowledge that which differentiates it from all other kinds of knowing. One to whom this sense has not opened itself thinks that self-knowledge arises in a way similar to knowledge through external senses, or through some other means acting from the outside. He thinks, “Knowledge is knowledge.” However, in one case its object is something situated in the external world, in the other case it is in his own soul. He hears only words, at best abstract thoughts, in what, for those who look deeper, constitutes the basis of their inner life namely, in the dictum that in all other kinds of knowing the object is outside of ourselves, while in self-knowledge we stand inside the object; that every other object comes into contact with us as something completed and closed, while in our self we actively and creatively weave what we observe in ourselves. This may appear as an explanation consisting of mere words, perhaps as a triviality, but if properly understood, it can also appear as a higher light which illuminates all other knowledge in a new way. He to whom it appears under the first aspect is in the same situation as a blind man to whom one says, A brilliant object is there. He hears the words, but for him brilliance does not exist. One can unite in oneself the sum of the knowledge of a period; if one does not perceive the significance of self-knowledge then in the higher sense all knowledge is but blind.