There are certain Arguments, which a Connoisseur is utterly to reject, as not being such by which he is to form his Judgement, of what Use soever they may be to those who are incapable of judging otherwise, or who will not take the Pains to know better. [...] One of the commonest, and most deluding Arguments, that is used on this Occasion is, that ‘tis of the Hand of such a One. Tho’ this has no great Weight in it, even admitting it to be Really of that Hand, which very often ‘tis not : The best Masters have had their Beginnings, and Decays, and great Inequalities throughout their whole Lives, as shall be more fully noted hereafter. That ‘tis done by one who has had great Helps, and Opportunities of improving himself ; Or One that Says, he is a great Master, is what People are very ready to be cheated by, and not one Jot the less, for having found that they have been so cheated again, and again before, nay, tho’ they justly laugh at, and despise the Man at the same Time.

There are such Peculiarities in the turn of Thought, and Hand to be seen in Some of the Masters (in Some of their Works especially) that ‘tis the easiest thing in the World to know them at first Sight ; such as Leonardo da Vinci, Michelangelo Buonarotti, Guilio Romano, Battista Franco, Parmeggiano, Paolo Farinati, Cangiagio, Rubens, Castiglione, and some others ; And in the Divine Raffaelle one often sees such a Transcendent Excellence that cannot be found in any other Man, and assures us this must be the Hand of him who was what Shakespear calls Julius Cæsar. The foremost Man of all the World.
There are several others, who by imitating other Masters, or being of the same School, or from whatsoever other Cause have had such a Resemblance in their Manners as not to be so easily distinguish’d, Timoteo d’Urbino, & Pellegrino da Modena, imitated Raffaelle ; Cæsare da Sesto, Leonardo da Vinci ; Schidone, Lanfranco, and others imitated Corregio ; Titian’s first Manner was a close imitation of that of Giorgione ;

After all it must be acknowledg’d that as in Other Sciences there are certain Branches of them wherein One Man excels, and Another in Others, but knows little of the rest ; So in Connoissance, No One Man can be acquainted with the Hands of All, even of the most considerable Masters ; nor with all the Manners perhaps of any One of those who have had great Variety of them ; Nor to be very Expert in more than a few of These : He must be contented with a Moderate Skill in many, and to be Utterly Ignorant in Some of them : Such is the Narrowness of our Faculties, the Extent of the Science, or the want of Helps, and Materials for the Study.
However let it be remember’d too That Every Connoisseur may judge concerning the Goodness of a Picture, or Drawing as to all the Parts of it except the Invention, and Expression in History, and the Resemblance in Portraits ; and these no One Man can judge Accurately of in All Cases, because no One Man can be acquainted with all the Stories, or Fables, or other Subjects of the Picture ; as no One Man can know Every Body.

in DA VINCI, Leonardo, Trattato della pittura di Lionardo da Vinci, novamente dato in luce, con la vita dell'istesso autore, scritta da Rafaelle Du Fresne. Si sono giunti i tre libri della pittura, & il trattato della statua di Leon Battista Alberti, con la vita del medesimo, TRICHET DU FRESNE, Raphaël (éd.), Paris, Jacques Langlois, 1651., p.1

in DU FRESNOY, Charles-Alphonse, De arte graphica liber, Paris, Nicolas Langlois, 1668., p.42

in DA VINCI, Leonardo, A Treatise of Painting by Leonardo da Vinci. Translated from the Original Italian, and adorn'd with a great Number of Cuts. To which is prefx'd, The Author's Life ; Done from The last Edition of the French, London, J. Senex - W. Taylor, 1721., p.29

in DE PILES, Roger et DU FRESNOY, Charles-Alphonse, The Art of Painting by C.A. DU FRESNOY with Remarks, trad. par DRYDEN, John, London, W. Rogers, 1695., p.59

in DU BOS, Jean-Baptiste, Critical Reflections on Poetry, Painting and Music, vol. 2, trad. par NUGENT, Thomas, London, John Nourse, 1748, 3 vol., vol. 2., p. 16

in DU FRESNOY, Charles-Alphonse et DE PILES, Roger, De Schilderkonst eerst in Latynze Vaerzen Beschreven door C.A. Dufresnoy in't Frans gebragt en met Aantekekeningen verrykt Door den Heer De Piles Nevens een Zaammeuspraak over het koloriet, trad. par VERHOEK, Joannes, Amsterdam, Balthazar Lakeman, 1722., p. 117

in DU BOS, Jean-Baptiste, Oordelkundige Aanmrkingen over de Poëzie, en Schilderkunst. Tweede Deel., trad. par ZWEERTS, Philip, Amsterdam, Jacobus Loeveringh, 1740., p. 22

in DA VINCI, Leonardo, Des vortreflichen Florentinischen Mahlers Lionardo Da Vinci Hoch-nützlicher Tractat von der Mahlerey, BÖHM, Johann Georg (éd.), Nürnberg, Johann Georg Böhm, 1724., p.2

in DU FRESNOY, Charles-Alphonse, Kurtzer Begriff Der Theoretischen Mahler-Kunst, trad. par GERICKE, Samuel Theodor, Berlin, Johann Michael Rüdigen, 1699., p.54