With all these concessions he realises, if I am not mistaken, that it is useless to look for a theory, in any strict sense of the word, in historical materialism; and even that it is not what can properly be called a _theory_ at all. He confirms us in this view by his fine account of its origin, under the stimulus of the French Revolution, that great school of sociology--as he calls it. The materialistic view of history arose out of the need to account for a definite social phenomenon, not from an abstract inquiry into the factors of historical life. It was created in the minds of politicians and revolutionists, not of cold and calculating _savants_ of the library. At this stage someone will say:--But if the theory, in the strict sense, is not true, wherein then lies the discovery? In what does the novelty consist? To speak in this way is to betray a belief that intellectual progress consists solely in the perfecting of the forms and abstract categories of thought. Have approximate observations no value in addition to theories? The knowledge of what has usually happened, everything in short that is called experience of life, and which can be expressed in general but not in strictly accurate terms? Granting this limitation and understanding always an _almost_ and an _about_, there are discoveries to be made which are fruitful in the interpretation of life and of history. Such are the assertions of the dependence of all parts of life upon each other, and of their origin in the economic subsoil, so that it can be said that there is but one single history; the discovery of the true nature of the State (as it appears in the empirical world), regarded as an institution for the defence of the ruling class; the proved dependence of ideals upon class interests; the coincidence of the great epochs of history with the great economic eras; and the many other observations by which the school of historical materialism is enriched. Always with the aforesaid limitations, it may be said with Engels: 'that men make their history themselves, but within a given limited range, on a basis of conditions actually pre-existent, amongst which the economic conditions, although they may be influenced by the others, the political and ideal, are yet, in the final analysis, decisive, and form the red thread which runs through the whole of history and guides us to an understanding thereof.