Of course, this argument is entirely reasonable, and debars us completely from chopping logic about the concrete examples Mr. Haldane has chosen. It is not his fault if his categories are so fine an instrument that nothing but the sum total of things can be taken to show us the manner of their use. It is simply our misfortune that he has not the sum total of things to show it by. Let us fall back from all concrete attempts and see what we can do with his notion of through-and-throughness, avowedly taken _in abstracto_. In abstract systems the "through-and-through" Ideal is realized on every hand. In any system, as such, the members are only _members_ in the system. Abolish the system and you abolish its members, for you have conceived them through no other property than the abstract one of membership. Neither rightness nor leftness, except through bi-laterality. Neither mortgager nor mortgagee, except through mortgage. The logic of these cases is this:--_If_ A, then B; but _if_ B, then A: wherefore _if_ either, Both; and if not Both, Nothing. It costs nothing, not even a mental effort, to admit that the absolute totality of things _may_ be organized exactly after the pattern of one of these "through-and-through" abstractions. In fact, it is the pleasantest and freest of mental movements. Husband makes, and is made by, wife, through marriage; one makes other, by being itself other; everything self-created through its opposite--you go round like a squirrel in a cage. But if you stop and reflect upon what you are about, you lay bare the exact point at issue between common sense and the "through-and-through" school.