Loquendum est ut plures

Praecipue cum est in furore suo

Loquendum est ut plures, sciendum autem ut sapientes – speak with the many (or 'the vulgar'), but think with the learned. Roger Bacon (Opus Maius, Volume 1, c. IV) compares the few who are called to the reception of divine truth to the few who shall accede to philosophical truth.

Nam multi sunt vocati, pauci vero electi ad veritatis divinae receptionem, et similiter philosophicae. Quare Philosophus dicit secundo Topicorum, quod sentiendum est ut pauci, licet loquendum sit ut plures; quia stultitiam vulgi aliquando simulare prudentia summa aestimatur, praecipue cum est in furore suo.

The reference is to the first chapter of book II of the Topics, although it is not clear where the Latin formulation comes from. Aristotle says:

Moreover, you should define what kind of things should be called as most men call them, and what should not. For this is useful both for establishing and for overthrowing a view: e.g. you should say that we ought to use our terms to mean the same things as most people mean by them, but when we ask what kind of things are or are not of such and such a kind, we should not here go with the multitude: e.g. it is right to call 'healthy' whatever tends to produce health, as do most men: but in saying whether the object before us tends to produce health or not, we should adopt the language no longer of the multitude but of the doctor.

In suo furore is biblical.

Who hath removed mountains, and they whom he overthrew in his wrath [in suo furore], knew it not [1].

The Lord shall trouble them in his wrath [in furore suo], and fire shall devour them" [2].

Aristotle's formulation, contrasts the many (or the 'vulgar', or the 'multitude') with the learned (the 'Doctor'). Another formulation contrasts the many with the few. "Loquendum est ut plures, sentiendum ut pauci" says Roger Bacon, adding 'scilicet ut sapientes' by way of explanation. See also his treatise on supposition.

Early modern

They who are convinced of the truth of the Copernican system do nevertheless say "the sun rises," "the sun sets," or "comes to the meridian"; and if they affected a contrary style in common talk it would without doubt appear very ridiculous.

There is an exact (English) formulation in Berkeley Principles 51, where he says that it sounds absurd to say that a spirit heats, rather than fire heats, or a spirit cools, rather then water cools. "Would not a man be deservedly laughed at, who should talk after this manner? I answer, he would so; in such things we ought to "think with the learned, and speak with the vulgar." " He notes that even though convinced of the Copernican system, we still say that the sun 'sets' or 'rises'.

Seventhly, it will upon this be demanded whether it does not seem absurd to take away natural causes, and ascribe everything to the immediate operation of Spirits? We must no longer say upon these principles that fire heats, or water cools, but that a Spirit heats, and so forth. Would not a man be deservedly laughed at, who should talk after this manner? I answer, he would so; in such things we ought to "think with the learned, and speak with the vulgar." They who are convinced of the truth of the Copernican system do nevertheless say "the sun rises," "the sun sets," or "comes to the meridian"; and if they affected a contrary style in common talk it would without doubt appear very ridiculous.

Hume nowhere mentions it explicitly, although he stands the principle on its head.

In considering this subject we may observe a gradation of three opinions, that rise above each other, according as the persons, who form them, acquire new degrees of reason and knowledge. These opinions are that of the vulgar, that of a false philosophy, and that of the true; where we shall find upon enquiry, that the true philosophy approaches nearer to the sentiments of the vulgar, than to those of a mistaken knowledge. ("Of the Ancient Philosophy", in the Treatise)

Links

• Henry of Ghent Quaestiones ordinariae, Art. XLI-XLVI "Cum igitur ad tale quid positivum significandum utimur principaliter in Deo hoc nomine {infinitum}, ponendum est simpliciter quod infinitum principaliter significat aliquid positive in Deo. Illud enim debet dici nominis significatum, ad quod significandum eo utimur communiter, quia «loquendum est ut plures», sicut dicit Philosophus. Bene tamen verum est, quod in hoc nomine <infinitum> positivo huic adnexa est negatio, quam significat ex ratione impositionis nominis. et hoc non primo et principaliter, sicut illi dicunt, sed secundario et ex consequente".
• Thomae de Sutton, On the plurality of forms "Hoc est quod dicit philosophus in Topicis, quod loquendum est ut plures, sciendum autem ut sapientes"
• In the article on Agostino Nifo Wikipedia says that "The famous phrase, to 'think with the learned, and speak with the vulgar' is attributed to Nifo." This is incorrect. While the phrase is found in Niphus's commentary on Aristotle de Gen. et Corr. Lib I f.29, it is clearly much earlier.