I write in order to attain that feeling of tension relieved and function achieved which a cow enjoys on giving milk.

Mencken frames writing not as lofty inspiration or moral mission but as a bodily, almost mechanical necessity: a pressure builds, and the act of writing releases it. By comparing himself to a cow being milked, he punctures romantic ideas about authorship and replaces them with a blunt, physiological metaphor of function and relief. The line also reflects Mencken’s characteristic irreverence—using earthy humor to demystify intellectual labor. Implicitly, the “reward” of writing is internal (tension relieved, function completed) rather than external (praise, money, posterity), suggesting that for some writers the compulsion to produce is its own justification.