orical one is not hopeless,
because throughout its long history Logic has been a practical
science; and, as I have tried to show at some length in introductory
chapters, has concerned itself at different periods with the risks of
error peculiar to each.

To enumerate the various books, ancient and modern, to which I have
been indebted, would be a vain parade. Where I have consciously
adopted any distinctive recent contribution to the long line of
tradition, I have made particular acknowledgment. My greatest
obligation is to my old professor, Alexander Bain, to whom I owe my
first interest in the subject, and more details than I can possibly
separate from the general body of my knowledge.

W. M.

ABERDEEN, _January, 1893_.

Since these sentences were written, the author of this book has
died; and Professor Minto's _Logic_ is his last contribution to the
literature of his country. It embodies a large part of his teaching in
the philosophical class-room of his University, and doubtless reflects
the spirit of the whole of it.

Scottish Philosophy has lost in him one of its typical
representatives, and the University of the North one of its most
stimulating teachers. There have been few more distinguished men than
William Minto in the professoriate of Aberdeen; and the memory of what
he was, of his wide and varied learning, his brilliant conversation,
his urbanity, and his rare power of sympathy with men with whose
opinions he did not agree, will remain a possession to many who mourn
his loss.

It will be something if this little book keeps his memory alive, both
amongst the students who owed so much to him, and in the large circle
of friends who used to feel the charm of his personality.

WILLIAM KNIGHT.

_GENERAL PLAN OF THE SERIES._

_This Series is primarily designed to aid the University Extension
Movement throughout Great Britain and America, and to supply the need
so widely felt by students, of Text-books for study and reference, in
connexion with the authorised Courses of Lectures._

_The Manuals differ from those already in existence in that they are
not intended for School use, or for Examination purposes; and that
their aim is to educate, rather than to inform. The statement of
details is meant to illustrate the working of general laws, and the
development of principles; while the historical evolution of the
subject dealt with is kept in view, along with its philosophical
significa