Known Knowns and Known Unknowns

Aeneas Silvius Piccolomini, de Educatione Liberorum IX:

“I would have them either educated (which is the best thing), or I would have them know that they are not educated. For, these is nothing worse than those who advance a little beyond the ABC’s and (to use Quintilian’s words), ‘put on a false cloak of learning.’

Ego illos aut eruditos esse voluerim, quod primum est, aut se non eruditos scire. Nihil enim peius est his, qui paululum aliquid ultra primas litteras progressi, ‘falsam sibi,’ ut Quintilianus verbis utamur, ‘scientiae persuasionem induerunt.’