Thomas Shadwell (1640-1692) was a comic playwright who considered himself the dramatic heir of Ben Jonson and the champion of the type of comedy Jonson had written, the "comedy of humours." Such plays allude to the medical theory that a healthy human body is composed of four humours kept in careful balance. Characters without such a balance have a predominant humour portrayed as a comic eccentricity. Dryden and Shadwell conducted a public argument for years on the merits of Jonson's plays. In the dedication to his play The Virtuoso, Shadwell claimed that "four of the humours are entirely new," and Dryden parodied this in his poem Mac Flecknoe:

This is thy province, this thy wondrous way,
New humours to invent for each new play;
This is that boasted bias of thy mind,
By which one way, to dullness, 'tis inclined;
Which makes thy writings lean on one side still,
And, in all changes, that way bends thy will.

—abstracted from The Norton Anthology of Poetry