"Take England. She is a democracy, if a masked one. Hence Jealousy is the dominating trait of her citizens. Jealousy has, thousands of years ago, invented railways, telegraphs, wired and wireless ones, telephones and Röntgen-rays, and all the rest of the infernal machines whereby Space, Time, and Work is shortened, curtailed, annihilated. Jealousy has at all times sent wireless messages over and through all the houses of a town or an entire country. It has Röntgenised the most hidden interiors; and its poison runs more quickly through all the veins and nerves of men than does the electric spark. "Look at the customs, social prejudices, or views of that nation. Over one half of them was introduced to disarm the ever-present demon of Jealousy. Why is a man a specialist? Because in that way he disarms Jealousy more quickly and more surely than by any other expedient. It gives him an air both of modesty and of strength by concentration. In reality it does neither. It is only an air. The so-called Reality consists of nothing but unrealities, of shams, and masks. A specialist is not a master of his subject; he is a master of the art than which there is no greater, the art of making other people believe that you are not what you are, but what _they_ want you to be. "Nature has a horror of specialists; and she will reveal her secrets to an insane poet rather than to a specialist. Most great inventions were made either by 'outsiders,' or by young men who had not yet had the time to harden into specialists. In specialisation there is nothing but a total misunderstanding of Nature. "Nature acts by instantaneous correlation and co-operation of different parts to one end; and to specialise is tantamount to taking a clock to pieces, putting them separately in a row on the table, and then expecting them to give you the exact time. "In Nature there is no evolution, but only co-evolution; there is no differentiation but only co-differentiation. The little ones have quite overlooked all that; and that is why so many of the statements of co-differentiation in my zoology can be neither confirmed nor refuted by them. Who dare say which is a 'part' in Nature? Is the hand a 'part,' that is, something that might legitimately be told off as a speciality? Or must it be studied in connection with the arm, or with its homologies in the nether part of the body? "In the same way: what constitutes a 'period' in history? Any division of a hundred or a thousand years by two, three, or four? Or by a division of twenty-five or thirty only? Who can tell? A man who says he is a specialist in the thirteenth century, is he not like a man who pretends that he is a specialist in respiration in the evening?