Where one acts by the common reason. A short theorem of safety. The condition: a work can be accomplished "according to the TERMreason common to gods and men" (κατὰ τὸν κοινὸν θεοῖς καὶ ἀνθρώποις λόγον) — the formula of the DOGMAcosmopolis (the same "common λόγος" of the sorites at 4.4: common mind → common law → fellow-citizens of gods and men). The consequence: ἐκεῖ οὐδὲν δεινόν — "there is nothing to fear." If an act is set within the rational order of the world, fear has no object: a rational act cannot lead to genuine evil.
Benefit without the risk of harm. The second half strengthens it: where one may "gain benefit (ὠφέλεια) through an activity that flows well (εὐοδοῦσα) and proceeds according to one's constitution (κατὰ τὴν κατασκευήν)" — there "no harm is to be suspected" (οὐδεμίαν βλάβην ὑφορατέον). The key is κατασκευή (the build, the constitution, as in 7.20, 7.55): an act that goes according to the doer's nature cannot turn into βλάβη in the Stoic sense, for the only real harm is the corruption of the ruling part (DOGMAthe invulnerability of the virtuous; cf. 7.22, 05-35). Hence the practical corollary: fear is in place only where I am ready to depart from reason; acting by it, I fear in vain. The governing discipline is action; the sustaining one, desire (the dissolution of fear).