A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects.
When you have worn out your shoes, the strength of the sole leather has passed into the fibre of your body. I measure your health by the number of shoes and hats and clothes you have worn out. He is the richest man who pays the largest debt to his shoemaker. [Emerson]