Terminology Tuesday: Sufficient Reason

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Principle of. The principle of sufficient reason arises out of modern rationalism, particularly as developed by Gottfried Leibniz (1646–1716). It was developed by Christian Wolfe and originally accepted by Immanuel Kant (1724–1804), though Kant subsequently rejected its metaphysical value, since he believed it led to contradictions and agnosticism.The principle claims that “Everything has a sufficient reason, either in another or in itself.” That is, there is either a sufficient reason outside of everything, or else it is its own sufficient reason. Leibniz believed that since the world was contingent, it had a sufficient reason outside of itself (in God). And the sufficient reason for God is inside himself.

Since “reason” for the world means “ground” or “cause,” then the principle of sufficient reason means that everything that exists has a cause, either outside itself or inside itself. It did not take philosophical agnostics (see AGNOSTICISM), such as Kant, or atheists, such as Arthur Schopenhauer (1788–1860), long to figure out that this either leads to an infinite regress (see INFINITE SERIES), or else to a self-caused being, which is impossible. If literally everything has a cause, either the series of causes never ends, or it ends in a being who caused its own being. Since nothing can lift itself from ontological nonbeing, then the very concept of God is contradictory. God could not exist.

Many critics of rational theism believe the principle of sufficient reason spells the end of all theistic arguments (see GOD, EVIDENCE FOR; GOD, OBJECTIONS TO PROOFS FOR) that use any causal premise (see COSMOLOGICAL ARGUMENT). This is not the case. There is a great difference between the principles of sufficient reason and cause. Criticisms of sufficient reason do not apply to the principle of causality (see CAUSALITY, PRINCIPLE OF). The latter was held by Thomas Aquinas, who never referred to any principle of sufficient reason, though some scholastic philosophers after Leibniz did mistakenly buy into it (see Gurr). The two principles are:

Principle of Sufficient Reason:	Principle of Causality:
1.  All things need a cause.	1. Contingent things need a cause.
2. God is the Ultimate Reason.	2. God is the only Ultimate Being.
3. God is a Self-Caused Being.	3. God is an Uncaused Being.

Geisler, N. L. (1999). Sufficient Reason, Principle Of. In Baker encyclopedia of Christian apologetics (p. 712). Grand Rapids, MI: Baker Books.

Geisler, N. L. (1999). Sufficient Reason, Principle Of. In Baker encyclopedia of Christian apologetics (p. 712). Grand Rapids, MI: Baker Books.

The principle of sufficient reason leads to a contradiction. The principle of causality does not. Leibniz’s principle leads logically to modern atheism. Aquinas’s principle leads to theism. The God of the principle of sufficient reason is a God of reason, not reality. The God of the existential principle of causality leads to a God who exists and, in fact, is existence itself (see GOD, NATURE OF). It is no more incoherent to have an uncaused God than for atheists to claim there is an uncaused universe. Nor is there an inherent logical contradiction in the concept of a Being who just is and ever has been.

Sources
  N. L. Geisler and W. Corduan, Philosophy of Religion  J. E. Gurr, The Principle of Sufficient Reason in Some Scholastic Systems, 1750–1900  I. Kant, The Critique of Pure Reason  G. Leibniz, Monadology  ———, Discourse on Metaphysics  Thomas Aquinas, Summa Theologica

Geisler, N. L. (1999). Sufficient Reason, Principle Of. In Baker encyclopedia of Christian apologetics (pp. 712–713). Grand Rapids, MI: Baker Books.