On November 9, 1785, he reported to Frau von Stein: “I go on reading Linne; I have to, since I have no other book with me. It is the best way to read a book conscientiously, which I must practice more frequently, since I do not easily read a book through to the end. This book was not made for reading, but for recapitulation, and it has done me the most valuable service, since I have thought about most of the points.”

During these studies, it became more and more clear to him that what appears in the endless multiplicity of single plant individuals is, after all, only one basic form; and this basic form itself became more and more manifest. He recognized, furthermore, that this basic form possesses the capacity for endless modifications, whereby manifoldness is created out of unity. On July 9, 1786, he wrote to Frau von Stein: “It is a becoming aware of the form with which nature, so to speak, always plays, and in playing brings forth manifold life.” What he now needed primarily to do was to develop into a plastic image in its details this enduring, constant element, this primal form with which, so to speak, nature plays. For this there was needed an opportunity to distinguish the truly constant, enduring element in the plant from the changing, unstable element. For observations of this kind Goethe had as yet investigated only a limited region. He had to observe one and the same plant under varied conditions and influences, for only thus does the changeable element become obvious. It is less easily observed in connection with plants of various kinds. All of this was afforded by the fortunate journey into Italy, which he began on September 3, from Karlsbad.

Even in connection with the flora of the Alps, many observations were made. He found there not only new plants which he had never seen, but also such as he already knew, but modified. “Whereas in the lower regions, the branches and stalks were stronger and more massive, the buds closer together, and the leaves broad, higher in the mountains the branches and stems were more delicate, the buds farther apart, so that a greater space occurred from joint to joint and the leaves took on a more spear-like shape. I noticed this in the case of a willow and a gentian, and was convinced that they were not different kinds. Also by Walchensee I noticed longer and slenderer rushes than in the lowlands.” Similar observations occurred repeatedly. In Venice, he noticed by the sea various plants which showed characteristics that only the ancient salt in the sandy soil, but still more the salt air, could give them. There he found a plant which appeared to him like our “harmless coltsfoot,” but armed with sharp weapons and with leaves like leather; the seed capsule also and the stalk were massive and fat. There Goethe saw the instability, the changeableness of all the external characteristics of plants, everything that belongs to their appearance. From this he drew the conclusion that the nature of the plant is not to be found in these characteristics, but must be sought at a deeper level.

It was from observations similar to those of Goethe that Darwin also proceeded when he asserted his doubt as to the constancy of the external forms of genera and species. But the conclusions which the two thinkers reached were entirely unlike. Whereas Darwin considered that the whole nature of the organism was, in fact, comprised in these characteristics, and came to the conclusion, therefore, that there is nothing constant in the life of the plant, Goethe went deeper and drew the inference that, since those characteristics are not constant, what is constant must be sought in something else which lies beneath changeable externalities. To give form to this latter element became Goethe's goal, whereas Darwin's efforts were directed toward searching into and explaining in detail the causes of that changeableness. Both methods of observation are necessary; they supplement each other. It is utterly erroneous to suppose that Goethe's greatness in organic science is to be found in the conception that he was a mere forerunner of Darwin. His mode of observation is far more comprehensive; it embraces two aspects: 1. the Type—that is, the entity of law manifest in the organism, the animality in the animal, the life evolving out of itself, which has the power and capacity, through the potentialities existing in it, to evolve in manifold external forms (species, genera); 2. the reciprocal action between the organism and inorganic nature, and between organisms among themselves (adaptation and the struggle for existence). Only the latter aspect of organics was developed by Darwin. It cannot be said, therefore, that Darwin's theory was the development of Goethe's basic ideas; it was the development of only one aspect of these ideas. It views only those facts which cause the world of living entities to evolve in a certain way, but not that “something” upon which those facts act determinatively. If only one aspect of the problem is inquired into, this can never lead to a complete theory of organisms. The inquiry must really be pursued in the spirit of Goethe; it must be supplemented and deepened through attention to the other aspect of this theory.

A simple comparison will make the matter clearer. Take a piece of lead, reduce it to a fluid by means of heat, and pour it into cold water. The lead has passed through two successive stages in its state of existence; the first was brought about by a higher temperature, the latter by a lower.