“If you are going to achieve excellence in big things, you develop the habit in little matters. Excellence is not an exception, it is a prevailing attitude.”

Attributed to Watson in: William G. Dickerson (1995) In search of the ultimate practice. p. 19.

His Biographers remark quoted in “Believing in Perfection” in New India Digest

November 11, 2013.
Tom Peters Daily, Weekly Quote

Don Soderquist “ Live Learn Lead to Make a Difference https://books.google.com/books?id=s0q7mZf9oDkC&lpg=pg=PP1&dq=Don%20Soderquist&pg=PP1#v=onepage&q&f=false, Thomas Nelson, April 2006 p. 58.
On Doing Things Right

Esar's Comic Dictionary

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Misattributed
Variant: We are what we repeatedly do, therefore excellence is not an act, but a habit.
Source: Will Durant, The Story of Philosophy: The Lives and Opinions of the World's Greatest Philosophers (1926), reprinted in Simon & Schuster/Pocket Books, 1991, ISBN 0-671-73916-6], Ch. II: Aristotle and Greek Science; part VII: Ethics and the Nature of Happiness: "Excellence is an art won by training and habituation: we do not act rightly because we have virtue or excellence, but we rather have these because we have acted rightly; 'these virtues are formed in man by his doing the actions'; we are what we repeatedly do. Excellence, then, is not an act but a habit: 'the good of man is a working of the soul in the way of excellence in a complete life... for as it is not one swallow or one fine day that makes a spring, so it is not one day or a short time that makes a man blessed and happy'" (p. 76). The quoted phrases within the quotation are from the Nicomachean Ethics, Book II, 4; Book I, 7. The misattribution is from taking Durant's summation of Aristotle's ideas as being the words of Aristotle himself.