One of his earliest publications reflected the findings of higher criticism in Old Testament studies concerning the identification of sub-sources and sub-documents within the first six books of the Bible (the Hexateuch).

The Documentary Hypothesis that Brightman drew upon had developed in Nineteenth Century German Biblical studies and had received their definitive form in the writings of Julius Wellhausen.

Wellhausen, and those who built on his theories, argued that the first five books of the Bible (the Pentateuch) were a composite creation drawing on four original sources and edited into their final form in the fourth century BC.

He also supported conscientious objectors in war, was a member of the American Civil Liberties Union, and also the Committee on Peace through Justice.

Bowne, who was a Methodist philosopher, emphasized the importance of personality and self-image, and encapsulated his ideas in the expression "transcendental empiricism".

In many ways Bowne's work on personality anticipated some of the views of Sigmund Freud, and even Albert Einstein's findings on the relativity of time and space.

In addition to building on Bowne's position, Brightman is credited with developing a metaphysical view in the philosophy of religion called finitistic theism.

Brightman's views about the growing and developing relationship between God and the world has strong affinities with process philosophy as espoused by Alfred North Whitehead and Charles Hartshorne.

Brightman's influence is also reflected in King's philosophy of Nonviolence, most markedly in the sixth and most fundamental principle of King's philosophy of Nonviolence, "The arc of the moral universe is long, but it bends toward justice" (the restatement of a metaphysical and ethical position articulated earlier by the Unitarian minister and abolitionist Theodore Parker (1810 - 1860)).