As generatio aequivoca leads to materialism, so Harvey’s formula leads to pure idealism. That these consequences should have been seen from the beginning, was so much the less to be expected since even today no such discovery has been made or could have been made, simply because no attention has been given to it. Hitherto the only question has been: Is Harvey’s formula a fact verified by natural science or not? In this form the battle has raged for over two centuries, often with great vehemence, and victory has leaned now to one side, now to the other. Finally, it was agreed that parentless generation was not to be found among the higher forms of animals and plants which could be observed with the naked eye. Büchner himself says it has not hitherto been discovered that any higher or more developed organism may be created by inorganic matter and forces alone.
“Today,” he says, “it seems to be a general law of the inorganic world that everything living originates from a parental embryo or else is directly segregated from the mother-body.”
But although spontaneous generation of the higher animals and plants seemed doubtful even to Büchner, nothing was at this time settled in regard to the origin of the lower organisms. With the discovery of the microscopical organic world, a new field and one more difficult of access was opened for research. It was now the sudden and unexpected appearance of bacteria, aspergillus and infusoria in places where their previous existence could not be imagined, that maintained the belief in generatio spontanea. But by and by we learned to understand the propagation and life also of these low organisms, their ability to withstand very high or very low temperatures, and the facility with which they are spread by the air and, above all, their rapid propagation. It commenced to be more and more evident that even in the micro-organic world no parentless generation exists. The investigations by Spallanzani, and later by Schultze, Schwann, von Dusch and Schröder, were epochal for the establishing of this fact. Their method, however, left some room for criticism which was forcefully pointed out by a great number of scientists, especially by the Englishman Needham.
During all these disputes Harvey’s formula had, however, won such a stability and approbation that Büchner himself under its pressure formulated his position in the following cautious words: “Even if recent scientific researches have more and more limited the ground for spontaneous generation, it is nevertheless not improbable that it even now takes place among the lowest and least developed organisms.”
It may willingly be conceded that this assertion was in its time by no means without foundation. But scarcely could Büchner or anybody else at that moment imagine how soon the hour of decision would strike. Shortly after 1860 the many centuries old question was finally settled almost simultaneously by Hoffman and Pasteur. Through the latter’s masterly investigations it was fully demonstrated that parentless generation does not exist in the micro-organic world either. Before Pasteur’s simple and clear evidence, opposition was silenced even so far that the question has almost entirely ceased to occupy our attention. Omne vivum ex vivo appears now to be an unchallenged truth. Life implies life.
But although science thus rejected generatio spontanea, the materialists nevertheless occupy a very strong position on the selfsame foundation as formerly, and continue the defense apparently not without some success.
In spite of Büchner’s real, or perhaps partly pretended, confidence, he seems to have had a presentiment of how weak the support of generatio spontanea was, and we find him therefore suddenly reasoning as if its cause were already lost. Thus he makes the entirely sound remark that even if at the present time all animals and plants must have parents, yet nothing whatever is thereby demonstrated in regard to the very first appearance of life in the universe. “If all organic beings have parents, how, then, did the first parents come into existence?” he asks. “When all outer conditions were favorable, might they not have appeared spontaneously, accidentally or necessarily? Or must the first organisms have been created through the intervention of some higher power?” Büchner concedes that this question is extremely complicated, and at first glance may appear unsolvable without the assumption of some such higher being who of his own will created the first organisms as it pleased him and endowed them with the faculty of propagation. “Orthodox scientists point with satisfaction also to this state of affairs,” says Büchner, “and they remind us at the same time of the artful and complicated structure of the world, and warmed by their conviction they see therein the wise arrangements of a higher, personal creator, who built the world according to his personal intentions.”
We might, according to Büchner, dismiss these orthodox thinkers with the assumption “that the first elements endowed with the idea of the race have been present in space from all eternity in formless chaos out of which the universe slowly consolidated, and accidentally developed after the formation and cooling of the planet wherever conditions were favorable.” But such fictitious reasonings or pretexts, Büchner assures us, are not necessary. Scientific facts, he says, indicate with great distinctness that the organic beings on our earth owe their generation and propagation to the co-operation of physical substances and forces alone.
After such an introduction we proceed with interest to learn about these scientific facts, but how great is our disappointment when we find that Büchner here takes up an entirely different subject, which, if it has any connection with the question at issue, goes to prove just the reverse of what he intended. The whole long series of facts to which he now points is, in a few words, nothing but Darwin’s theory in a paleontological light. What Büchner shows by numerous examples from fossil deposits, is that higher forms of animals and plants have slowly developed from lower forms. But what has this fact to do with generatio spontanea? That higher forms have developed from lower forms only confirms the dictum that life implies life; in other words, supports Harvey’s law. But it is something else that Büchner should have demonstrated. He should instead have shown us that the first organisms owe their existence to physical forces alone. But on this subject he uses only vague expressions, void of any real significance, about the slow cooling off of the earth; about the length of the geological periods, and about favorable conditions; but not a line to explain what this word “favorable” stands for.
Although Büchner here inadvertently supports something different from what he intended, his remark nevertheless remains true that the present mode of propagation proves nothing in regard to the generation of the first organisms.