“Self-interest speaks all sorts of languages and plays all sorts of parts.”François de La Rochefoucauld · Maxime · 1665 · Maxima 39
Self-interest has no convictions, only costumes: it speaks whichever language pays.
Self-interest is versatile: it speaks the language of faith with believers, of commerce with partners, of affection with friends. The mechanism is camouflage — we pursue our own advantage under the mask each situation demands. Example: a salesperson who suddenly becomes the customer's "friend," switching the same warmth from one profile to another.
Why it matters It helps you read the real motives behind pleasant speeches, especially in negotiations and marketing.