In Religion and the One, Frederick Copleston investigates the metaphysical relationship between the One and the Many found within both religious and philosophical enquiry. These lectures attempt to synthesize the “natural” or philosophical theology envisaged by Lord Gifford with the interest of non-western cultures espoused during his advanced years. This enquiry leads Copleston to conclude that the activity of synthesizing many empirical facts on the metaphysical level culminates in an elusive project of understanding the One.
Whilst acknowledging that inductive metaphysics is a natural and legitimate mental activity, Copleston asserts in his introductory essays that one should not be surprised at the plurality of world-views in response to the question of the One and the Many. Various philosophies and theological systems acknowledge the existence of the transcendent One with the Many encountered in everyday experience.
In the second set of lectures (chapters 3-6), Copleston investigates the ways in which both Western philosophy and non-Western religions seek to address the transcendence and immanence of the One and the Many. Thus, Taoism and Buddhism both reject the idea that a transcendent ultimate reality is distinct from the phenomenal world, while Advaita Vedanta identifies the One with the Absolute whose plurality can only be seen from a higher point of view than that of everyday life. In terms of Islam, Copleston seeks to demonstrate the historically close connection between philosophy and mystical spirituality in the line of Islamic thought, between the eleventh century and the nineteenth century. Finally, the diachronic connection between metaphysics and religion in the West addresses the unity and infinity of God found within historical Christian theology.
In the third set of lectures (chapters 7-9), Copleston investigates the epistemic importance of how the Many of sense-perception can understand the One based upon inference. This line of argumentation centers upon the natural movement of the human mind to analyze the various entities within the world and synthesize them into a unified reality. This attention to the individual leads naturally into a consideration of the Self and the One, in which the human individual is able to view the world as both correlative and distinct. Whilst he acknowledges that there are different degrees of awareness of the divine presence, Copleston concludes that suprasensory mystical experiences must be coupled with empirical and philosophical enquiry.
Finally, Copleston turns his attention toward the ethical and social ideals that result in humanity’s search for truth (chapters 10-11). Whilst theoretically possible to separate ethical injunctions from metaphysical or theological assumptions, moral language should be viewed through the forms of life that will lead to a philosophical anthropology situated within a wider context. As such, religious interest and metaphysics, combined with the limitations of language, converge and culminate to a certain point in mysticism. Yet, a correspondence theory of truth means that metaphysical considerations must be grounded within empirical data to produce the positive concepts of God that are necessary for religion in its devotional and social aspects.