Sir Joshua Reynolds, Discourse Four, 1771, focusing on the distinction between colour and design warns that Titian and the Venetian painters should be studied 'cautiously', and this is confirmed, he says, by the greatest of all authorities, Michelangelo:
This wonderful man, after having seen a picture by Titian, told Vasari, who accompanied him, 'that he liked much his colouring and manner' but then he added, that' it was a pity that Venetian painters did not learn to draw correctly 'in their early youth and adopt a better manner of study'. By this it appears that the principal attention of the Venetian painters, in the opinion of Michael Angelo, seemed to be engrossed by the study of colours, to the neglect of the ideal beauty of form, or propriety of expression. ( Reynolds, Discourses, p.66)
An example is given in Reynolds on Bacchus and Ariadne in Discourse Eight.
In Discourse Eleven, 1782, Reynolds develops the point:
We cannot entirely refuse to Titian the merit of attending to the general form of his object, as well as colour: but his deficiency lay, a deficiency at least when he is compared with Raffaelle, in not possessing the power, like him, of correcting the form of his model by any general idea of beauty in his own mind. ( Reynolds, Discourses, p. 196)
At MP I:84 Ruskin seems to mount a direct, though not explicit, challenge to the standards applied by Reynolds (and beyond Reynolds, by Vasari, Le Vite, Testo VI.164) in his comments on Bacchus and Ariadne, and, at MP I:146, in his comments on the relationship between Titian and the two brothers Bellini.