From Robert Anson Heinlein:

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.

And now for a slightly modified version (as seen on c2wiki by Peter Merel):

A programmer should be able to fix a bug, market an application, maintain a legacy, lead a team, design an architecture, hack a kernel, schedule a project, craft a class, route a network, give a reference, take orders, give orders, use configuration management, prototype, apply patterns, innovate, write documentation, support users, create a cool web-site, email efficiently, resign smoothly. Specialization is for recruiters.