Page:Ferrier's Works Volume 1 - Institutes of Metaphysic (1875 ed.).djvu/324

296PROP. XI.———— to know; in other words, in conception some element essential to cognition may be left out."

7. But what would happen if we could think or represent less than we could know, or have presented to us? This would happen, that we should be able to represent what could not be known or presented to us, because less than what can be known cannot possibly be known; and, therefore, if less than what can be known could be thought of or represented, something could be thought of or represented which could not be known. But it has been proved by this proposition, and it is a necessary truth of reason, that neither we nor any intelligence can think or represent what we cannot know or have experience of; and, consequently, we cannot think of less than we can know: in other words, this counter-proposition, the progeny of psychology and inadvertent thinking, is false and contradictory. We are indebted for it to the psychological doctrine of "abstraction" which has been already animadverted on (Prop. VI., Obs. 32.)

8. This proposition fixes the unit or minimum of thought as commensurate, in its essential constituents, with the unit or minimum of cognition. It fixes object (some thing or thought) plus subject as the unit of subsequent cogitation, just as Propositions II. and III., fixed this as the unit of antecedent or original cognition. It was necessary to