It’s in Walden’s second chapter, Where I Lived, and What I Lived For, that Thoreau’s famous quotes on simplicity and simplify occur.
Here’s the context (italics mine):
Our life is frittered away by detail. An honest man has hardly need to count more than his ten fingers, or in extreme cases he may add his ten toes, and lump the rest. Simplicity, simplicity, simplicity! I say, let your affairs be as two or three, and not a hundred or a thousand; instead of a million count half a dozen, and keep your accounts on your thumb nail. In the midst of this chopping sea of civilized life, such are the clouds and storms and quicksands and thousand-and-one items to be allowed for, that a man has to live, if he would not founder and go to the bottom and not make his port at all, by dead reckoning, and he must be a great calculator indeed who succeeds. Simplify, simplify. Instead of three meals a day, if it be necessary eat but one; instead of a hundred dishes, five; and reduce other things in proportion.
He exclaims the noun simplicity three times, yet quietly mentions the verb simplify twice. (I suspect for a master wordsmith such as Thoreau this is no accident. )
Still, five mentions the root word simple is something to take note of, and for me, this is one of the most important paragraphs in the phiisophical literature on how I can live a good life.