Note 244 — FIFTH ENNEAD, BOOK FIVE. That Intelligible Entities Are Not External to the Intelligence of the Good.

We see here an assertion of the standpoint later asserted by Berkeley, Kant and Hegel that the mind cannot go outside itself, and that consequently it is the measure of all things. Kant's "thing-in-itself," a deduction from this, was already discovered by Plotinos in the result of the "bastard reasoning" process, which Hegel called "dialectic."