Here is the section from Letter to Menoeceus (Saint Andre translation) that is relevant to this discussion:
"For he holds that we are responsible for what we achieve, even though some things happen by necessity, some by chance, and some by our own power, because although necessity is not accountable he sees that chance is unstable whereas the things that are within our power have no other master, so that naturally praise and blame are inseparably connected to them. [note] Indeed he sees that it would be better even to cleave to the myths about the gods (since that leaves some hope of prevailing upon them through worship) than to be subject to the destiny of the scientists (since that way lies an inexorable necessity). [note] And such a man holds that Fate is not a god (as most people believe) because a god does nothing disorderly, and he holds that Fate is not an uncertain cause because nothing good or bad with respect to a completely happy life is given to men by chance, although it does provide the beginnings of both great goods and great evils."