G. CROOM ROBERTSON, M.A.,

PROFESSOR OF PHILOSOPHY OF MIND AND LOGIC IN UNIVERSITY COLLEGE, LONDON.

SECOND EDITION, WITH ADDITIONS.

LONDON: JOHN MURRAY, ALBEMARLE STREET.
1880.

The right of Translation is reserved.

PRINTED BY WILLIAM CLOWES AND SONS,
LONDON:
STAMFORD STREET AND CHARING CROSS.