Finally, socialistic speculation has in many cases tended, not to reform and humanise, but to subvert the family, on the soundness of which social health above all things depends. It has not understood the solidity and value of the hereditary principle in the development of society. Socialists have, in short, been far too ready to attack great institutions, which it must be the aim of all rational progress, not to subvert, but to reform and purify. In the socialistic treatment of other questions, such as capital, rent and interest, the same defects of arbitrariness and absoluteness are apparent. But the extravagances of the historic socialism are so obvious that they confute themselves, and we shall not dwell on this aspect of our subject. We must remember that most historic systems have had to run themselves clear of the turbid elements with which they were originally mixed. Socialism, considered both as a movement and as a system of economic thought, is still in process of development. Its theories must undergo the rough-hewing of continual controversy, discussion, and criticism. The whole movement must pass through the test, the tear and wear of experience, under the conditions prescribed by history and the fundamental laws of human nature, before its ideals can hope to be wedded to fact. We might add that it will receive the purification of experience; only, we have to lament that it is the fate of our ideals to submit also to the degradation of experience. A like charge of abstractness may justly be brought against the two great German economists, Adolf Wagner and Schäffle, whose writings have so largely promoted a better comprehension of socialism. Their economic works are monuments of learning and lucidity, but their exposition and interpretation of the subject are marked by that excessive love of system which is usually characteristic of German specialists. They have brought to the discussion of the historic socialism the same systematising spirit with which German economists have treated Adam Smith. The economists of the Fatherland have reduced the teaching of Adam Smith to a set of abstract propositions, and so have transformed it beyond recognition. In like manner Adolf Wagner laboriously sums up socialism in abstract language, whereas it is above all things a concrete movement, instinct with change and with human passion. In his _Bau und Leben des sozialen Körpers_ Schäffle’s construction of socialism is an elaborate attempt to conceive society as transformed and dominated by a single principle.