οὐ γὰρ ἐναργές ἐστι τὸ ἐπιτήδευμα τοῦτο, ὥστε κατ᾽ ἀνάγκην, κ.τ.λ. The alternative reading is ἐν ἀρχαῖς. It has been suggested to read, ὅτε γὰρ…τότε (for τοῦτο), and understand an aposiopesis in the next sentence; thus—“For when our undertaking is clear and simple, then we must entrust to ourselves the decision of what is best. But when the attempt at the unknown is not unattended with risk—(then we want a guide).” Billius. But this is very awkward.