Originally published in 1919, this book is an outgrowth of classroom discussions. It contains in substance the talks on economics which have been made, for the past eleven years, to the author's classes in Cornell and New York Universities. The time has long since passed when a single volume can treat exhaustively the whole field of economics; designed as an introduction, this book will servce as a means to the end of a more intelligent study of economic questions and prepares the mind of the student for the thought contained in the more advanced and specialized works on the subject and the practical applications they reveal.