On the Happy Life (or De vita beata), Stoic treatise by Seneca written around 58 AD. JC, defines happiness as virtue and agreement with reason (nature), and not as the possession of material goods.
The work responds to critics accusing Seneca of hypocrisy (a wealthy Stoic) by establishing that:
The sovereign good resides in virtue, which provides indestructible inner autonomy in the face of the vagaries of fortune. Riches, exile or death are "indifferent": they do not harm the wise if he is not emotionally attached to them. The happy life is that which follows right reason, allowing one to enjoy external goods without becoming a slave to them. Ultimately, happiness is a stable moral state, accessible only through self-control and detachment from the ephemeral pleasures advocated by Epicureanism.