Fruit-bearing as a universal law. Marcus widens the ordinary "to bear fruit" (φέρειν καρπόν) far beyond the vine: fruit is borne by man, by god, and by the whole TERMcosmos — each "in its own season" (ἐν ταῖς οἰκείαις ὥραις). That habit (συνήθεια) has fixed the word to the grape is mere narrowness of usage, "nothing to the point" (οὐδὲν τοῦτο). The move is the same as in the image MOTIF"everything that exists is a seed" (4.36): to count only the literal as fruit is "very vulgar"; in truth every nature is productive.
The fruit of reason is the rational. The climax: TERMλόγος has a "twofold" fruit — DOGMAcommon (κοινόν) and its own (ἴδιον) — and from it are produced "other things of the same kind as it is itself" (τοιαῦθ’ ἕτερα, ὁποῖον αὐτός). Reason reproduces the rational: right judgements, right acts, the very cast of a rational soul. Hence the double reference — to DOGMAsociability (the fruit of reason is not only "mine" but for all) and to the productivity of nature. The governing discipline is action (the fruit of reason is a deed), the sustaining one desire (to accept one's "own season" as the vine does).