“There are five stages in scientific work: observation, experiment, recordal, reflection, generalisation. Through all these five stages Darwin and Marx, as scientific men, went. Darwin, as we have seen, observed and experimented upon plants and animals for twenty-eight years before he announced his great discovery. He recorded the results of these observations and experiments. In his study at Down, besides the printed books, the microscopes, the pots and pans in which his experiments were going on, there were countless note-books containing the record of what he had observed, read of, and seen as the result of experiment. Upon this record he reflected, and as the result of his reflection made a generalisation, or rather a series of generalisations. This last and highest stage in scientific work is only reached by the highest. Many others can observe, experiment, record, and reflect. But only the rarer souls can generalise ; that is, can draw out of the multitude of observed and recorded phenomena some one connecting, unifying principle, some golden thread linking together all the multitude of details and producing order out of chaos. These generalisations, these verbal expressions of some general principle running through a mass of individual facts, are often badly called “laws of nature”. The misfortune of the name is that ordinary people think that there is something in common between a law of nature and a law of government or of society. Perhaps the only thing they have in common is the misleading name “law”. A law of nature is a generalisation, i.e., the verbal expression of certain observed sequences or coincidences in natural phenomena. A law of society or of government is a decree promulgated by the society or the government to direct the conduct of human beings. Hence, only very loose thinking could give rise to the fallacy that a law of nature implies a law-giver. To avoid the possibility of that loose thinking it would be better to drop altogether the phrase “law of nature” and to use only the word “generalisation”. (…) “Another difference between the two is that Marx was the more universal man. Darwin was a geologist and biologist pure and simple. He read with difficulty any other language than his own, and, as far as I know, spoke no language but English. He confessed to me personally that he had no read Shakespeare for many years. His letter already quoted shows that economic science was not studied by him. On the other hand, Marx read practically every European language, and wrote and spoke perfectly, English, French, and German. His knowledge of the general literature of all countries was immense” (…) “Indirectly, a great deal has already been said about the characters of Darwin and Marx. Their physical appearance was in harmony with those characters. Both were men of singularly commanding presence as well as personality. Their faces, even as only known to us by portraits, are full of remarkable strength and beauty. Compare, for example, the pictures of Darwin with, say, those of the various gentlemen who profess to satisfactorily reconcile the teachings of Darwin with those of the orthodox people. Or compare the head of Marx with, say, that of the present German Emperor. Head, eyes, body, manner, with both these men proclaim them kings among men; whilst the others possess only the ordinary characteristics or ordinary citizens. In both Darwin and Marx there was that beautiful modesty without affectation characteristic of the highest minds. They had none of the affected mock modesty that you and I suffer from. And their moral character was on the same level with their intellectual character. Truth, rectitude, purity, marked those characters. They both seemed to have an instinct for what is right in life as well as in science. Altogether two very beautiful natures. And therefore necessarily the subject of calumny and misrepresentation. Their critics were not content with attacking their theories. They assailed the men in their private characters. The foulest statements were made about the private lives of both men. And in the case of Marx at a time when no newspaper in Europe would open its columns to any refutation of the calumnies. However, Darwin and he lived it all down ; and – this rare – outlived it. Before their death the world knew them both, not as their intimates knew them, but as men of the very highest and most irreproachable moral character” [Edward Aveling, ‘Charles Darwin and Karl Marx: A Comparison’, The New Century Review’, March-April, 1897]