As the author of this volume states, the science of logic does not stand still. This book was intended to cover the advances made in the study of logic in the first half of the nineteenth century, during which time the author felt there to have been greater advances made than in the whole of the preceding period from the time of Aristotle. Advances which, in her eyes, were not present in contemporary text books. As such, this book offers a valuable insight into the progress of the subject, tracing this frenetic period in its development with a first-hand awareness of its documentary value.