"A good book, in the language of the book-sellers, is a salable one; in that of the curious, a scarce one; in that of men of sense, a useful and instructive one"

In this quote, Oswald Chambers is assessing how a "excellent book" can be specified in different methods, depending upon the perspective of the individual doing the assessing. According to book-sellers, a great book is one that will offer well and make them money. To the curious, an excellent book is one that is tough to find or rare. However, Chambers argues that from the perspective of people who value intelligence and knowledge, a truly great book is one that works and includes important details or guideline.