Diogenes, exiled from Sinope around 410 BCE after his father's mint scandal, defaced coins literally, then set out to deface the currency of custom. He lived in a storage jar, owned a cup until he saw a boy drink from his hands, and answered Alexander's offer of any favor with: stand out of my light. Athens called him the Dog, kyon, and his school the Cynics, kynikoi. A rival etymology cites the Cynosarges gymnasium where Antisthenes taught, but the dog stuck.
Dog was a slur for shamelessness. The Cynics accepted the brand and reverse-engineered a philosophy from it: dogs live by nature, need little, bark at fools, fawn on friends. When asked why he was called the Dog, Diogenes explained: I fawn on those who give, bark at those who refuse, and bite scoundrels. The modern meaning, distrust of all sincerity, is the insult without the philosophy, the bark without the argument.
The claim: modern cynicism is Cynicism with the hope removed, the original dogs rejected convention to live more honestly, while the modern cynic rejects sincerity to risk less; the word traveled from moral extremism to emotional hedging. Verdict: sharp and mostly fair, though Sloterdijk argued the modern version is enlightened false consciousness, knowing better and doing it anyway. The Dog would bite us either way.
When did the dog's-eye view of humanity become a diagnosis instead of a philosophy?