The materialism of the last century was predominantly mechanical, because at that time, of all natural sciences, only mechanics, and indeed only the mechanics of solid bodies -- celestial and terrestrial -- in short, the mechanics of gravity, had come to any definite close. Chemistry at that time existed only in its infantile, phlogistic form. [8] Biology still lay in swaddling clothes; vegetable and animal organisms had been only roughly examined and were explained by purely mechanical causes. What the animal was to Descarte, man was to the materialists of the 18th century -- a machine. This exclusive application of the standards of mechanics to processes of a chemical and organic nature -- in which processes the laws of mechanics are, indeed, also valid, but are pushed into the backgrounds by other, higher laws -- constitutes the first specific but at that time inevitable limitations of classical French materialism.
The second specific limitation of this materialism lay in its inability to comprehend the universe as a process, as matter undergoing uninterrupted historical development. This was in accordance with the level of the natural science of that time, and with the metaphysical, that is, anti-dialectical manner of philosophizing connected with it. Nature, so much was known, was in eternal motion. But according to the ideas of that time, this motion turned, also eternally, in a circle and therefore never moved from the spot; it produced the same results over and over again.
This conception was at that time inevitable. The Kantian theory of the origin of the Solar System [that the Sun and planets originated from incandescent rotating nebulous masses] had been put forward but recently and was still regarded merely as a curiosity. The history of the development of the Earth, geology, was still totally unknown, and the conception that the animate natural beings of today are the result of a long sequence of development from the simple to the complex could not at that time scientifically be put forward at all. The unhistorical view of nature was therefore inevitable.
We have the less reason to reproach the philosophers of the 18th century on this account since the same thing is found in Hegel. According to him, nature, as a mere "alienation" of the idea, is incapable of development in time -- capable only of extending its manifoldness in space, so that it displays simultaneously and alongside of one another all the stages of development comprised in it, and is condemned to an eternal repetition of the same processes. This absurdity of a development in space, but outside of time -- the fundamental condition of all development -- Hegel imposes upon nature just at the very time when geology, embryology, the physiology of plants and animals, and organic chemistry were being built up, and when everywhere on the basis of these new sciences brilliant foreshadowings of the later theory of evolution were appearing (for instance, Goethe and Lamarck). But the system demanded it; hence the method, for the sake of the system, had to become untrue to itself.
This same unhistorical conception prevailed also in the domain of history. Here the struggle against the remnants of the Middle Ages blurred the view. The Middle Ages were regarded as a mere interruption of history by a thousand years of universal barbarism. The great progress made in the Middle Ages -- the extension of the area of European culture, the viable great nations taking form there next to each other, and finally the enormous technical progress of the 14th and 15th centuries -- all this was not seen.
Thus a rational insight into the great historical interconnectedness was made impossible, and history served at best as a collection of examples and illustrations for the use of philosophers.
The vulgarizing pedlars, who in Germany in the fifties dabbled in materialism, by no means overcame this limitation of their teachers.
All the advances of natural science which had been made in the meantime served them only as new proofs against the existence of a creator of the world; and, indeed, they did not in the least make it their business to develop the theory any further. Though idealism was at the end of its tether and was dealt a death-blow by the Revolution of 1848, it had the satisfaction of seeing that materialism had for the moment fallen lower still. Feuerbach was unquestionably right when he refused to take responsibility for this materialism; only he should not have confounded the doctrines of these itinerant preachers with materialism in general.
Here, however, there are two things to be pointed out. First, even during Feuerbach's lifetime, natural science was still in that process of violent fermentation which only during the last 15 years had reached a clarifying, relative conclusion. New scientific data were acquired to a hitherto unheard-of extent, but the establishing of interrelations, and thereby the bringing of order into this chaos of discoveries following closely upon each other's heels, has only quite recently become possible.
