Sidney was so far from writing with sang froid [as Walpole claimed] …that he was apt rather to run into the other extreme; his blood seems now and then to boil too high, and his imagination almost always places him in the situation of the very persons he describes.
Sheridan expresses his enthusiasm for Arcadia in an early letter from the period just before his emergence as a successful dramatist. As he is aware, this is an (uncharacteristically) unfashionable interest. The novel was increasingly dominant, as testified by the reference to Fielding and Smollett here and by the many recent examples of the genre borrowed by Lydia Languish from the circulating library (The Rivals (1775), Act I, Scene ii).
Sheridan considers Sidney further in a draft letter to the Queen, also probably written in 1772 (Letters, ed. Price, vol. 1, p. 58): ‘How different is the character of Sidney and Agrippa, from that of the modern man of fashion and gallantry. In one there is the Soul of Honour, the true Spirit of Love, the dear delightful extravagance of Gallantry, the romance of Virtue. His Friend is as himself. His honour his God. His life is the active separation of the nobler passions, and luminous feelings.’
My Heart made me wish to be your Friend, before my Judgement could inform me of your Character. And if I did not feel a Confidence that I am not mistaken, I would never trust either Heart