THIS BOOK is not intended as an abstruse scientific work, but the statement of a new theory, and its comparison with the old ones for the instruction of the masses. It is well said, " every age has its predominant thought."

That of Greece was beauty, and she excelled in sculptured grace of statue and temple ; that of Rome was power and she conquered the world ; that of the sixteenth century was reform, and states and religions were torn into warring fections ; that of the eighteenth century w...