In writing this book I have taken it as a commonplace that everyone—man, woman, and child—wants to be strong. Without strength—and by strength I mean health, vitality, and a general sense of physical well-being—life is but a gloomy business. Wealth, talent, ambition, the love and affection of friends, the pleasure derived from doing good to those about one, all these things may afford some consolation for being deprived of life’s chief blessing, but they can never make up for it. “But,” I ...