“30. “Of the desires, some are natural and necessary, some natural, but not necessary, and some are neither natural nor necessary, but owe their existence to vain opinions.” (Epicurus thinks that those are natural and necessary which put an end to pains, as drink when one is thirsty; and that those are natural but not necessary which only diversify pleasure, but do not remove pain, such as expensive food; and that these are neither natural nor necessary, which are such as crowns, or the erection of statues.) 31. “Those desires which do not lead to pain, if they are not satisfied, are not necessary. It is easy to impose silence on them when they appear difficult to gratify, or likely to produce injury. 32. “When the natural desires, the failing to satisfy which is, nevertheless, not painful, are violent and obstinate, it is a proof that there is an admixture of vain opinion in them; for then energy does not arise from their own nature, but from the vain opinions of men.” — Diogenes Laertius, *Lives of Eminent Philosophers*, Book X, Sec. XXXI, Maxims 30–32, trans. C. D. Yonge (1853). **Surface Gloss:** Desires split into three classes: natural-necessary (ending pain), natural-unnecessary (merely varying pleasure), and unnatural-unnecessary (status symbols). When a non-painful natural desire feels violent and obsessive, its heat comes from corrupted social opinion, not nature. The **Obsession Diagnostic**: how do you tell whether an intense craving (for a specific hire, a luxury acquisition, a romantic target, or a market win) is a real structural need or an ego-hallucination? Run the two-step Epicurean test: First, if I walk away right now, does it cause actual structural damage ("pain"), or just a missed variation? Second, if it causes no structural damage yet my craving feels "violent and obstinate," the energy driving me is 100% synthetic narrative ("vain opinion") — not the thing itself.
— In our words · Source: Lives of Eminent Philosophers (Diogenes Laertius)