Moral Letters to Lucilius Section 3

Adice nunc, quod nemo eorum, qui in re publica versantur, quot vincat, sed a quibus vincatur, aspicit. Et illis non tam iucundum est multos post se videre quam grave aliquem ante se. Habet hoc vitium omnis ambitio; non respicit. Nec ambitio tantum instabilis est, verum cupiditas omnis, quia incipit semper a fine.

ils sont moins flattés de laisser mille rivaux derrière eux que rongés d’en voir un seul qui les précède. C’est le vice de toute ambition de ne point regarder derrière elle. Et ce n’est pas l’ambition seule qui ne s’arrête jamais ; toute passion fait de même :

Besides, no man in public life thinks of the many whom he has outstripped; he thinks rather of those by whom he is outstripped. And these men find it less pleasing to see many behind them than annoying to see anyone ahead of them. That is the trouble with every sort of ambition; it does not look back. Nor is it ambition alone that is fickle, but also every sort of craving, because it always begins where it ought to end.