De vulgari eloquentia (I, xvi, 1-6)

(1) Postquam venati saltus et pascua sumus Ytalie nec pantheram quam sequimur adinvenimus, ut ipsam reperire possimus, rationabilius investigemus de illa ut, solerti studio redolentem ubique et necubi apparentem nostris penitus irretiamus tenticulis. (1) Now that we have hunted across the woodlands and pastures of all Italy without finding the panther we are trailing, let us, in the hope of tracking it down, carry out a more closely reasoned investigation, so that, by the assiduous practice of cunning, we can at last entice into our trap this creature whose scent is left everywhere but which is nowhere to be seen.
(2) Resumentes igitur venabula nostra, dicimus quod in omni rerum genere unum oportet esse quo generis illius omnia comparentur et ponderentur et quod velut aliorum omnium mensuram accipiamus; sicut in numero cuncta mensurantur uno, et plura vel pauciora dicuntur secundum quod distant ab uno vel ei propinquant; et sicut in coloribus omnes albo mensurantur; nam visibiles magis dicuntur et minus, secundum quod accedunt vel recedunt ab albo. Et quemadmodum de hiis dicimus que quantitatem et qualitatem ostendunt, de predicamentorum quolibet, et etiam de substantia posse dici putamus; scilicet, unumquodque mensurabile fit secundum quod in genere est, illo quod simplicissimum est in ipso genere. (2) Accordingly, I take up my equipment once more for the hunt, and state that in any kind of thing there needs to be one instance with which all others can be compared, against which they can be weighed, and from which we derive the standard by which all others are measured. Thus, in arithmetic, all numbers are measured by comparison with the number one, and are deemed larger or smaller according to their relative distance from or closeness to that number. Likewise with colours, all are measured against white, and held to be brighter or darker as they approach or recede from that colour. And I hold that what can be said of things that have quantity and quality is also true of any predicate whatever, and even of substances: in short, that everything can be measured, in so far as it belongs to a genus, by comparison with the simplest individual found in that genus.
(3) Quapropter in actionibus nostris, quantumcunque dividantur in species, hoc signum inveniri oportet quo et ipse mensurentur. Nam, in quantum simpliciter ut homines agimus, virtutem habemus, ut generaliter illam intelligamus; nam secundum ipsam bonum et malum hominem iudicamus; in quantum ut homines cives agimus, habemus legem, secundum quam dicitur civis bonus et malus; in quantum ut homines latini agimus, quedam habemus simplicissima signa, et morum et habituum et locutionis, quibus latine actiones ponderantur et mensurantur. (3) Therefore, when dealing with human actions, in so far as these can be allotted to different categories, we must be able to define a standard against which these too can be measured. Now, in so far as we act simply as human beings, we possess a capacity to act - a 'virtue', if we understand this in a general sense - and according to this we judge people to be good or bad. Insofar as we act as human beings who are citizens, we have the law, by whose standards we can describe a citizen as good or bad; insofar as we act as human beings who are Italians, there are certain very simple features, of manners and appearance and speech, by which the actions of the people of Italy can be weighed and measured.
(4) Que quidem nobilissima sunt earum que Latinorum sunt actiones, hec nullius civitatis Ytalie propria sunt et in omnibus comunia sunt: inter que nunc potest illud discerni vulgare quod superius venabamur, quod in qualibet redolet civitate nec cubat in ulla. (4) But the most noble actions among those performed by Italians are proper to no one Italian city, but are common to them all; and among these we can now place the use of the vernacular that we were hunting above, which has left its scent in every city but made its home in none.
(5) Potest tamen magis in una quam in alia redolere; sicut simplicissima substantiarum, que Deus est, in homine magis redolet quam in bruto animali; in bruto animali quam in planta; in hac quam in minera; in hac quam in elemento; in igne quam in terra. Et simplicissima quantitas, quod est unum, in impari numero redolet magis quam in pari; et simplicissimus color, qui albus est, magis in citrino quam in viride redolet. (5) Its scent may still be stronger in one city than another, just as the simplest of substances, which is God, is more clearly present in human beings than in animals, in animals than in plants, in plants than in minerals, in minerals than in the basic element, and in fire than in earth; or as the simplest quantity, one, is more apparent in odd numbers than in even; or as the simplest colour, white, shines more visibly in yellow than in green.
(6) Itaque, adepti quod querebamus, dicimus illustre, cardinale, aulicum et curiale vulgare in Latio, quod omnis latie civitatis est et nullius esse videtur, et quo municipalia vulgaria omnia Latinorum mensurantur, ponderantur, et comparantur. (6) So we have found what we were seeking: we can define the illustrious, cardinal, aulic, and curial vernacular in Italy as that which belongs to every Italian city yet seems to belong to none, and against which the vernaculars of all the cities of the Italians can be measured, weighed, and compared.