He was a strident moral idealist who stated in 1909 that, to him, idealism meant "to interpret life consistently with ethical, scientific, and metaphysical truth."

Perry's viewpoints on religion stressed the notion that religious thinking possessed legitimacy should it exist within a framework accepting of human reason and social progress.

[4][5] A pupil of William James, whose Essays in Radical Empiricism he edited (1912), Perry became one of the leaders of the New Realism movement.

Puritanism and Democracy (1944) is a famous wartime attempt to reconcile two fundamental concepts in the origins of modern America.

[2] Their son was Edward Barton Perry born at their home 5 Avon Street in Cambridge, September 27, 1906.