Of course the explanation of this strange attitude on the part of these philosophers is simple enough; they have a wrong conception of substance and of the relation of accidents thereto; they appear to imagine that according to the traditional teaching nothing of all we can discover about accidents—or, as they prefer to term them, “phenomena”—can possibly throw any light upon the nature of substance: as if the rôle of phenomena were to cover up and conceal from us some sort of inner core (which they call substance), and not rather to reveal to us the nature of that “being, existing in itself,” of which these phenomena are the properties and manifestations. The denial of substance leads inevitably to the substantializing of accidents. It is possible that the manner in which some scholastics have spoken of accidents has facilitated this error.(235) Anyhow the error is one that leads inevitably to contradictions in thought itself. Mill, for instance, following out the arbitrary postulates of subjectivism and phenomenism, finally analysed all reality into present sensations of the individual consciousness, _plus_ permanent possibilities of sensations. Now, consistently with the idealistic postulate, these “permanent possibilities” should be nothing more than a certain tone, colouring, quality of the “present” sensation, due to the fact that this has in it, as part and parcel of itself, feelings of memory and expectation; in which case the “present sensation,” taken in its concrete fulness, would be the sole reality, and would exist in itself. This “solipsism” is the ultimate logical issue of subjective idealism, and it is a sufficient _reductio ad absurdum_ of the whole system. Or else, to evade this issue, the “permanent possibilities” are supposed to be something really other than the “present sensations”. In which case we must ask what Mill can mean by a “permanent _possibility_”. Whether it be subjective or objective possibility, it is presumably, according to Mill’s thought, some property or appurtenance of the individual consciousness, _i.e._ a quality proper to a subject or substance.(236) But to deny that the conscious subject is a substance, and at the same time to contend that it is a “permanent _possibility_ of sensation,” _i.e._ that it has properties which can appertain only to a substance, is simply to hold what is self-contradictory.