He opens with a vigorous protest that there can be no quarrel about the materialism of science with the “spiritual” and the “privately-orthodox.” Such people must regard all investigation of “this world” as aimless. The only thing of value for them is “the next world”; the best attitude towards _this_ life is as crass an ignorance as possible, and so all science is worthless. The words are so sharp that he was interrupted and had to explain that he was not attacking anybody personally. He was only speaking “with the candour of a scientific worker, who is in the habit of calling things by their proper names.” (At this point there was some applause.) Hence he is not speaking of materialism, he says, on that account, but because of certain objections from men of science, who said that philosophic speculation led us out of our way. Schleiden had branded the theory of man as a cell-state, the conception of man as, not an absolute, but a federal unity, as materialism. But this conception is not a philosophical theory at all; it is a fact. It is a piece of scientific truth, like the law of gravitation. He recurred to the old and often-quoted definition: the kind of research that brings such facts to light has nothing whatever to do with philosophy. On the other hand, “materialism,” in so far as it expresses a general theory of the world, is a philosophy. Hence the simple investigation of facts as such can neither be dubbed materialistic nor said to have a philosophic tinge. There are many objections to this strict delimitation of the provinces of the human mind, as Virchow lays it down in the old style. It is true that materialism is a real philosophy, especially in the form current at the time and given to it by Vogt and Büchner. But it is a question whether we see, observe, or investigate at all, if we completely exclude philosophy; whether the philosophic thought can be really pumped out of even the most rigorous and exact “observation of facts,” like air in the air-pump; whether there are any such things as purely objective “facts” in this sense in any human brain. And it is also a question whether the facts, however objectively we regard them, do not arrange themselves, when they are numerous, in logical series, which force us to draw conclusions as to the unknown by the very laws of probability; in other words, whether they do not always produce a “philosophy” in the long run. However, these questions are all well within the pure atmosphere of science. It is Virchow’s practical conclusions that are interesting; and he goes on to draw them freely.