If wisdom is the true criterion of freedom, the principal burden of slavery shifts from the outer to the inner, from the physical to the mental, and philosophy not manumission becomes the source of liberty.A. A. LongThe Author of this QuoteAuthorA. A. LongProfessor of the Graduate School and Chancellor's Professor Emeritus of Classics and Irving G. Stone Professor Emeritus of Literature; Affiliated Professor of Philosophy and Rhetoric.