The trouble with Kant, according to Anthony Quinton (Philosophy 72 [1997], 5–18), is that he does not take empirical experience to have any significant role to play in our knowledge of the world. The world we know is constituted through the imposition of a priori forms — space, time, substance and cause — on a ‘wholly passive sensory raw material’ This sensory material does not guide the manner in which the a priori forms are imposed in any way, so that the imposition is ‘entirely arbitrary’. Thus, Kant's ‘account of the matter allows for an indefinitely large number of orders in which our successive manifolds of sensation could be arranged. None of these ways of distinguishing what there is and occurs from what I merely think is and occurs has any priority or superiority to any of the others’ (Quinton, 17–8).