PROP. XVII.————
selves, therefore they have an occult substratum, and this occult substratum is substance. Well, let this postulation be granted. Can the qualities, together with their substance, be now conceived as subsisting by themselves? Not one whit better than before. They still (that is, the qualities and the substance together) require an additional supplement before they can be conceived as subsisting; they require to be supplemented in knowledge, or in thought, by the known or conceived "me" before they can be known or thought of at all (Props. I. and XIII.) It is thus obvious that psychological substance does not answer the purpose for which it was intended. It was postulated because the qualities could not be conceived as standing alone; but just as little can the qualities plus the substance be conceived as standing alone; therefore the hypothesis is good for nothing. It offers to the material qualities a support which breaks down under them—a very questionable kindness.
Secondly, It places before us the mere phenomenal.10. Secondly, This opinion is, moreover, misleading; it places before us the mere phenomenal and calls it the substantial. Whatever can be known or thought of only when something else is known or thought of along with it is the phenomenal (see Definition). Phenomena, with the addition of the substratum, which psychology calls substance, can be known or thought of only when the ego is