A philosophical dualist, Frost regarded spirit and matter as the two basic elements of reality. Human nature itself was composed of spirit and matter, or body and soul. As for religion, science, art, politics, and history, each was a different form of revelation. They were metaphors aimed at illuminating the True, the Good, and the Beautiful for the mind of man. Though he belonged to no church or sect, Frost admitted to being “an Old Testament Christian.” He accepted the Law of Moses in the Decalogue and believed justice between God and man, and justice between men, was paramount. He was highly critical, therefore, of those who sentimentalized Christ’s teachings through doctrines like universal salvation that neglected justice not only in religion but in every aspect of man’s life in society.
Frost greatly respected science and its contributions toward man’s knowledge of the laws and operations of the universe. Scientists were to Frost among the “heroes” of modern civilization; their “revelations” proved the ability of man to penetrate and harness matter through the mind. But as a religious man and humanist, Frost also believed there were mysteries about both matter and spirit that were beyond the reach of science. And while the methods of the physical sciences applied to matter, they could not be applied with equal validity to human nature and society because man is more than a biological animal. There is a qualitative difference between matter and human nature, most evident in the religious, moral, intellectual, aesthetic, and social values recognized or created by man. Therefore, Frost believed, science could not shape the world toward utopian ends any more than could politics.
It was the function of poetry and the arts, Frost felt, to strive for the final synthesis and unity between spirit and matter. In fact, he defined poetry as the only way mankind has of “saying one thing and meaning another, saying one thing in terms of an other.” The revelations of art, as well as those of religion, transcend those of science by providing human values and meaning in the universe and in human affairs. Art’s revelations are not merely of knowledge, but include insight and love; they involve not only recognition but also response, beginning in ecstatic aesthetic pleasure and ending in calm moral wisdom. Whereas science is like a prism of light cast on a particular point of nature to reveal its laws and operations, the arts are like the sun that shines on all alike, unleashing man’s aesthetic and moral imagination upon the whole of creation.
In his social and political philosophy, Frost provided a powerful defense of the American republic through his criticism of attacks upon it by Marxists, international pacifists, and New Deal liberals. Against Marxist collectivism and the welfare state, Frost defended individual liberty as an end in itself. He rejected the rationalist politics of the Left and put his faith in the historical continuity of Western civilization, in the tested moral traditions of the Judeo-Christian religion, in classical liberal education, in the philosophical thought of such thinkers as Aristotle, Kant, Burke, and William James, and especially in the political philosophy of the founding fathers of the American republic. In his reverence for the American constitutional system, Frost was a strict constructionist.