Our intellectual process derives from that which is directly and individually concrete, by successive stages of increasing abstraction, which are always vindicate as legitimate by their ultimate derivation from that which is concrete and individual, to which reference may always be made as a means of control. The properties of each thing in itself or its relations to others, or the group of which it forms a part, or the order in which it presents itself as regards others, give rise to the essences or "eidos" of property, relation, group, order in general, which form a concatenation of essences subordinated to some category regarded as supreme. If we apply this to the process followed by EUCKEN we see how we gradually separate, from a whole formed by an apparently inextricable heterogeneity of elements, by means of successive interrelated and intersubordinated intuitions and abstractions, the concrete historical individual reality. Following on with more general concepts, by successive abstractions we build up different economic systems.