nevertheless always get back into pure duration, of which the moments are internal and heterogeneous to one another, and in which a cause cannot repeat its effect since it will never repeat itself. [Sidenote: Kant regarded both space and time as homogeneous.] In this very confusion of true duration with its symbol both the strength and the weakness of Kantianism reside. Kant imagines on the one side "things in themselves," and on the other a homogeneous Time and Space, through which the "things in themselves," are refracted: thus are supposed to arise on the one hand the phenomenal self--a self which consciousness perceives--and, on the other, external objects. Time and space on this view would not be any more in us than outside us; the very distinction of outside and inside would be the work of time and space. This doctrine has the advantage of providing our empirical thought with a solid foundation, and of guaranteeing that phenomena, as phenomena, are adequately knowable. Indeed, we might set up these phenomena as absolute and do without the incomprehensible "things in themselves," were it not that the Practical Reason, the revealer of duty, came in, like the Platonic reminiscence, to warn us that the "thing in itself" exists, invisible but present. The controlling factor in the whole of this theory is the very sharp distinction between the matter of consciousness and its form, between the homogeneous and the heterogeneous, and this vital distinction would probably never have been made unless time also had been regarded as a medium indifferent to what fills it. [Sidenote: But if time, as duration, were homogeneous, science could deal with it.] But if time, as immediate consciousness perceives it, were, like space, a homogeneous medium, science would be able to deal with it, as it can with space. Now we have tried to prove that duration, as duration, and motion, as motion, elude the grasp of mathematics: of time everything slips through its fingers but simultaneity, and of movement everything but immobility. This is what the Kantians and even their opponents do not seem to have perceived: in this so-called phenomenal world, which, we are told, is a world cut out for scientific knowledge, all the relations which cannot be translated into simultaneity, i.e. into space, are scientifically unknowable. [Sidenote: And freedom would be incomprehensible. Kant's solution.]