Definition of "solitariness"

In both a mazefull ſolitarineſſe: / In night of ſprites the gaſtly powers to ſtur, / In thee or ſprites or ſprited gaſtlineſſe: […]

c. 1580s, Philip Sidney, “Astrophel and Stella”, in Mary Sidney, editor, The Countesse of Pembrokes Arcadia […] [The New Arcadia], 3rd edition, London: […] [John Windet] for William Ponsonbie, published 1598, sonnet 96, page 564

I saw a Deane of S. Hillarie of Poictiers, reduced by reason and the incommoditie of his melancholy to such a continuall solitarinesse, that when I entered into his chamber he had never removed one step out of it in two and twenty yeares before […].

1603, Michel de Montaigne, chapter 8, in John Florio, transl., The Essayes […], book II, London: […] Val[entine] Simmes for Edward Blount […]

So much as doing good is better than not doing evil, will I account Christian good fellowship better than an eremitish and melancholy solitariness.

1646, Joseph Hall, The Balm of Gilead