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, analyse a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects.
In pursuit of learning, every day something is acquired. In pursuit of Tao, every day something is dropped.
Don't do anything that someone else can do. Don't undertake a project unless it is manifestly important and nearly impossible.
There is surely nothing other than the single purpose of the present moment. A man's whole life is a succession of moment after moment. If one fully understands the present moment, there will be nothing else to do, and nothing else to pursue. Live being true to the single purpose of the moment. Everyone lets the present moment slip by, then looks for it as though he thought it were somewhere else.
If a warrior is not unattached to life and death, he will be of no use whatsoever. The saying that "All abilities come from one mind" sounds as though it has to do with sentient matters, but it is in fact a matter of being unattached to life and death. With such non-attachment one can accomplish any feat.
Meditation on inevitable death should be performed daily. Every day when one's body and mind are at peace, one should meditate upon being ripped apart by arrows, rifles, spears and swords, being carried away by surging waves, being thrown into the midst of a great fire, being struck by lightning, being shaken to death by a great earthquake, falling from thousand-foot cliffs, dying of disease or committing seppuku at the death of one's master. And every day without fail one should consider himself as dead.