He says so explicitly in the Letter to Demetriade : you, being of a noble family, have much wealth, many honors, but these goods, even though they belong to you, are not really yours, because you’ve inherited them, but virtue instead is yours only, because only you can reach it, it’s only in your hands.
Lo dice explícitamente en la Carta a Demetriada : tú, siendo de noble familia, posees muchas riquezas, muchos honores, pero estos bienes, pese a que te pertenecen, no son verdaderamente tuyos, porque los has heredados; la virtud, en cambio, es un bien solo tuyo, porque solo tú la puedes alcanzar, está solo en tus manos.