Kant and Hartshorne on the Ontological Argument

Distinctively modern philosophical thought has been characterized by the premise that competing answers to metaphysical questions about the nature of reality in its ultimate and most comprehensive sense are incapable of rational adjudication on the grounds that metaphysics as a mode of inquiry illegitimately seeks to transgress the inherent limits of what it is possible for human beings to know. Agnosticism as to what is ultimately real is the weaker form of this quintessentially modern objection to metaphysics, whereas atheism or the denial of any meaningful intellectual content to metaphysical claims whatsoever is its stronger form. This premise signifies the crucial break with Western philosophy’s classical and medieval past, for which a metaphysical knowledge of reality as such was, with few exceptions, considered indispensable to religious and moral affirmations.¹ To be sure, some notable post-Enlightenment philosophers have expressly dissented from this premise (e.g., Hegel and Whitehead) and, to that extent, their thought, however distinctively modern in other respects, has not been representative of modernity’s anti- or post-metaphysical tendencies. Nevertheless, much of the most brilliant and creative theological thinking within the modern era has been undertaken precisely within the constraints of modernity’s philosophical rejection of metaphysics. One has only to think of such influential figures as Schleiermacher, Kierkegaard, Ritschl, Barth, Bultmann, Buber, Bonhoeffer, and Ebeling, who faced the modern situation in philosophy with resolve and daring. Whatever their individual differences from one another may have been, they were united in the quest to find a basis for religious faith apart from dependence upon every form of “natural theology” that claims to have knowledge of God’s existence derived from philosophical reason alone.

Although ours is an age often described as “postmodern,” it can hardly be said that modernity’s characteristic premise regarding metaphysics has now been set aside or overcome. To the contrary, those forms of contemporary philosophy most illustrative of the postmodern spirit have only intensified modern metaphysical skepticism. In spite of their critical posture toward modernism in general, they tend to accept its anti- or post-metaphysical stance as a matter of course. In this respect, so-called “postmodernism” does not represent a break with what is essentially modernist.² But surely it must be the case that any truly critical assessment of modernity should also interrogate its axiom that metaphysical questions about reality as such are beyond reason’s capacity to answer.

Initially, this metaphysical skepticism was not the starting point of modern philosophical argument but, rather, its conclusion. Shaken by the radical empiricism of David Hume (1711–1776) as well as by his searing critique of the traditional “proofs” for God’s existence, Immanuel Kant (1724–1804) inaugurated a new era in philosophical reflection that entailed a decisive break with classical metaphysics. Kant’s “Copernican Revolution” consisted in a thorough rethinking of the relation obtaining between the empirical and rational elements in human cognition for the purpose of securing the foundations of modern science against the threat of their dissolution by Hume’s empiricism. While endorsing Hume’s verdict as to the theoretical inadequacy of the arguments adduced in support of natural theology, Kant nonetheless sought to identify a practical basis for belief in God through reflection upon the presuppositions of the moral life. Thereby, he charted an alternative course for modern religious thought that was adopted by many theologians, Christian and Jewish, who agreed with his epistemological conclusion as to the impossibility of validating belief in God through metaphysical argument.³ If this modern skepticism as to the possibility of metaphysical knowledge is to be effectively challenged, Kant’s answer to Hume needs to be carefully re-examined.

The traditional arguments for God’s existence fall into two broad types. Unlike the “cosmological” and “physico-theological” (or “teleological”) arguments that proceed inductively from some general characterization of observable experience to the inference of God’s probable existence, the “ontological argument” proceeds deductively from what is considered to be a logically self-evident definition of deity to the conclusion of God’s necessary existence. The ontological argument, which found its classical expression in the Proslogion of Anselm...