Before and after Cicero, it was common to comlain of the deficiencies of Latin as a philosophical language. Cicero protested, with some justice, that new subjects in any language require the creation of new words, and that Greek philosophers too had resorted to neologisms. He himself introduced, for example, qualitas, moralis, and beatitudo, for 'quality', 'moral', and 'happiness' (it is suggestive that Rome, left to herself, needed no word for happiness).When I learned Latin at school I was taught that the word for happiness was felix, but that this really meant good luck rather than the meaning captured in Galt's Speech:
[Ch.19, "Cicero and Rome" by Miriam Griffin, p. 458.]
So Republican Rome had no concept of an earned happiness! That sort of figures: all those stories about violated virgins committing suicide to escape dishonour and statesmen preferring to execute their own sons than deviate from the letter of the law...
Happiness is the successful state of life, pain is an agent of death. Happiness is that state of consciousness which proceeds from the achievement of one's values.")
[Galt's Speech, in For the New Intellectual and Atlas Shrugged]
The Greek concept of happiness wasn't quite the same as ours either, though it seems a lot closer: Jonathan Barnes notes in Aristotle that Aristotle used the term eudaimonia, which means 'flourishing' - a successful life and the activity required to achieve it - rather than the state of consciousness that might be expected to proceed from flourishing.