All who henceforth strove for higher cognition had to come to terms with this expanded sensory world. In earlier centuries the meditating spirit of man had stood before another world of facts. Now it was given a new task. It was no longer the things of this Earth alone which could express their nature out of the interior of man. This interior had to enfold the spirit of a sensory world which fills the spatial universe everywhere in an identical fashion. — It was such a task that confronted the thinker from Nola, Philotheo Giordano Bruno (1548–1600). The senses have conquered the spatial universe for themselves; now the spirit is no longer to be found in space. Thus man was directed from outside to seek the spirit henceforth only where, on the basis of deep inner experiences, it had been sought by the glorious thinkers who have been discussed in the preceding expositions. These thinkers draw out of themselves a conception of the world to which men later are to be compelled by a more advanced natural science. The sun of ideas which later is to fall upon a new conception of nature, with them is still beneath the horizon, but its light already appears as a dawn in a time when men's thoughts about nature are still enveloped in the darkness of night. — For the purposes of science the sixteenth century gave the heavens to that world of the senses to which they rightfully belong; up to the end of the nineteenth century this science had progressed so far that from among the phenomena of plant, animal, and human life also it could give to the world of sensory facts what belongs to it. Neither up in the ether nor in the development of living organisms can this science henceforth look for anything but factual-sensory processes. As the thinker of the sixteenth century had to say: The Earth is a star among stars, subject to the same laws as other stars, so the thinker of the nineteenth century must say: “Whatever his origin and his future may be, for anthropology man is only a mammal; specifically he is that mammal whose organization, needs, and diseases are the most complicated, and whose brain, with its wonderful capacity, has reached the highest degree of development.” (Paul Topinard,Anthropologie, Leipzig, 1888, p. 528.) — On the basis of this point of view attained by science, a confusion of the spiritual with the sensory can no longer take place, if man understands himself aright. An advanced science makes it impossible to seek in nature a spirit conceived along the lines of the material, just as sound thinking forces us to seek the cause of the advance of the hands of a clock in the laws of mechanics (the spirit of inorganic nature), not in a special demon who causes the movement of the hands. As a scientist, Ernst Haeckel justifiably had to reject the clumsy conception of a God thought of in the same way as something material. “In the higher and more abstract forms of religion this corporeal manifestation is abandoned, and God is worshiped only as ‘pure spirit,’ without body. ‘God is a spirit and he who worships Him must worship Him in spirit and in truth.’ Nevertheless, the spiritual activity of this pure spirit is exactly the same as that of the anthropomorphous, divine personality. In reality this immaterial spirit too is not thought of as incorporeal, but as invisible, gaseous. We thus come to the paradoxical conception of God as a gaseous vertebrate.” (Haeckel, Welträtsel [The Riddle of the Universe], p. 333.) In reality, a sensory-factual existence of something spiritual can only be assumed where an immediate sensory experience shows the spiritual; and only that degree of the spiritual can be assumed which is perceived in this manner. The excellent thinker B. Carneri could say (in the work Empfindung und Bewusstsein [Sensation and Consciousness], p. 15): “The sentence 'No spirit without matter, but also no matter without spirit' would justify us in extending the problem also to plants, or even to the first rock we come across, where hardly anything could be said in favor of this correlation.” Spiritual processes, as facts, are the results of different functions of an organism; the spirit of the world does not exist in the world in a material manner, but only in a spiritual manner. The soul of man is a sum of processes in which the spirit appears most immediately as a fact. But it is only in man that the spirit exists in the form of such a soul. And to seek the spirit in the form of a soul elsewhere than in man, to think of other beings as endowed with a soul like man, is to misunderstand the spirit; it is to commit the most grievous sin against the spirit. One who does this, only shows that he has not experienced the spirit itself within him; he has only experienced the external manifestation of the spirit that holds sway in him: that is, the soul. But this is just as if somebody were to mistake a circle drawn in pencil for the true mathematical-ideal circle. One who does not experience within himself anything but the soul-form of the spirit feels impelled to assume such a soul-form also in non-human things, in order not to have to stop at gross sensory materiality. Instead of thinking of the primordial foundation of the world as spirit, he thinks of it as a world soul, and assumes a general animation of nature.
Giordano Bruno, under the impact of the new Copernican conception of nature, could grasp the spirit in the world, from which it had been expelled in its old form, only as a world soul. When one immerses oneself in Bruno's writings (especially in his profound book Of the Cause, the Principle, and the One) one has the impression that he thought of things as being animated, although in different degrees. He has not in reality experienced the spirit within himself; therefore he imagines it in terms of the human soul, in which form alone it has confronted him. When he speaks of the spirit he understands it in this way. “The universal reason is the innermost, most real, and most characteristic faculty, and is a potential part of the world soul; it is something everywhere identical, which fills the All, illuminates the universe, and instructs nature in bringing forth its species as they should be.” It is true that in these sentences the spirit is not described as a “gaseous vertebrate,” but as a being like the human soul. “A thing, however small and minute, has within itself a portion of spiritual substance which, if it finds the substratum to be suitable, strives to become a plant or an animal, and organizes itself into a body of some kind, which is generally called animated. For spirit is to be found in all things, and there is not the most minute body which does not contain such a portion of it that it animates itself.” — Because Giordano Bruno had not really experienced the spirit as spirit within himself, he could confuse the life of the spirit with the external mechanical functions by means of which Raimon Lull (1235–1315), in his so-called Great Art, had attempted to unveil the mysteries of the spirit. A modern philosopher, Franz Brentano, describes this Great Art as follows: “On concentric, individually turnable circular disks various concepts were inscribed, and then the most diverse combinations were produced by this means.” What coincidence superimposed upon a particular turn, was formed into a judgment about the highest truths. And in his many wanderings about Europe, Giordano Bruno appeared at various universities as a teacher of this Great Art. He had the boldness to think of the stars as worlds that are completely analogous to our Earth; he enlarged the vision of scientific thinking beyond the Earth; he no longer thought of the heavenly bodies as corporeal spirits, but he still thought of them as spirits of the soul. One must not do an injustice to this man whom the Catholic church made to atone for his advanced ideas with death. It was an enormous achievement to enfold the whole heavens in the same conception of the world that up to that time had been applied only to the things of the Earth, even though Bruno still thought of the sensory as of something belonging to the soul. —