An ounce of action is worth a ton of theory.

This expression is widely misattributed to Emerson in journalism, tweets, and memes on the internet. This quotation in an earlier phrasing of Jared Eliot's statement “It used to be the Saying of an old Man, That an Ounce of Experience is better than a Pound of Science.” (Essays upon Field Husbandry, 1748; quotation reprinted in "Jared Eliot, Minister, Physician, Farmer" by Rodney H. True. Agricultural History Vol. 2, No. 4 (Oct. 1928), p199). The quote has also been misattributed to Friedrich Engels, a claim possibly originating from the 1975 book The Strange Case of Victor Grayson by Reg Groves (link)