Found in a footnote to Christopher Celenza’s edition of Angelo Poliziano’s Lamia but originally from Apuleius’ Florida (15.22-25). Poliziano – see bottom for the full passage – had echoed and tweaked the phrase rudimentum sapientiae.
Tot ille [Pythagoras] doctoribus eruditus, tot tamque multiiugis calicibus disciplinarum toto orbe haustis, vir praesertim ingenio ingenti ac profecto super captum hominis animi augustior, primus philosophiae nuncupator et conditor, nihil prius discipulos suos docuit quam tacere, primaque apud eum meditatio sapienti futuro linguam omnem coercere, verbaque, quae volantia poetae appellant, ea verba detractis pinnis intra murum candentium dentium premere. Prorsus, inquam, hoc erat primum sapientiae rudimentum: meditari condiscere, loquitari dediscere
Educated by so many masters, and after draining so many cups of knowledge of such different kinds throughout the world, that master of truly great genius [Pythagoras], more venerable than the human mind can encompass, the first to give a name and foundation to philosophy, made silence the first lesson he taught his students, and the first exercise of the would-be philosopher in his school was to suppress all speech and, stripping the feathers from those words that poets call “winged,” to imprison them within “the wall of shining teeth.” This, I repeat, was absolutely their first exercise in philosophy—to learn meditation and to unlearn chatter.
And Poliziano’s modified reference in the opening of Lamia:
Fabulari paulisper lubet, sed ex re, ut Flaccus ait; nam fabellai, etiam quae aniles putantur, non rudimentum modo sed et instrumentum quandoque phiosophiae sunt.
Le’ts tell stories for a while, if you please, but let’s make them relevant, as Horace says. For stories, even those that are considered the kinds of things that foolish old women discuss, are not only the first beginnings of philosophy. Stories are also – and just as often – philosophy’s instrument.