"the Arnold and the Arden Shakespeare"

 Matthew Arnold (1822-1888) was an influential poet and cultural critic. His main work of literary criticism Essays in Criticism was published in 1865.

The Arden Shakespeare is a series of scholarly editions of the works of William Shakespeare, first published by Methuen between 1899 and 1925. The series continues to be published to this day, currently under the Bloomsbury imprint.