Indiscernibility & Contingent Creation

Question #19: How, within a Catholic metaphysical framework, does the principle of the indiscernibility of identicals avoid making God’s creative act necessary, thus preserving the Church’s insistence on creation’s contingency (CCC 296–298)?

In modern philosophy, the indiscernibility of identicals (often attributed to Leibniz) states that if two things are truly identical, then whatever is true of one is true of the other. Applied to God, one might worry that if God’s creative act is identical to His essence, then everything true of God’s essence (including its necessity) also applies to creation–thus making creation itself necessary. However, within a Catholic metaphysical framework, theologians emphasize crucial distinctions that preserve contingency (CCC 296–298) without undermining divine simplicity or the principle of indiscernibility of identicals.

1. Distinguishing “God’s Act in Himself” from “the Effect in Creation”

Catholic theology holds that the act by which God wills creation is indeed identical with God’s essence. Yet we must differentiate between God’s own act (which is fully and eternally one with Him) and the effect that act produces in the created order. While God Himself is necessary (He cannot not be), the content or outcome of His will–i.e., “this universe” rather than “no universe” or “some other universe”–is not necessary. Thus, the principle of indiscernibility of identicals affirms that there is no internal division in God (His essence and His will are one), but it does not require that creation share in God’s necessity.

2. No Contradiction Between God’s Necessary Being and Free Decree

The principle of indiscernibility of identicals applies to God’s internal reality: to say “God’s act is God’s essence” means there is no composition in God. This fact does not force all of God’s choices to be necessary in the sense that He “had no other option.” Rather, classical Catholic thought (Aquinas, for instance) teaches God freely decrees creation. The necessity is internal to God’s being–He necessarily exists–but there remains freedom in what He wills regarding creatures. Therefore, the necessity that belongs to God does not spill over onto the finite effect in creation.

3. Contingency on the Creature’s Side

From the created perspective, the world genuinely could have been otherwise–or might not have been at all. This real contingency is grounded in God’s free determination. God’s eternal act might be necessary to God’s nature (because there is no “part” of God that could be otherwise), yet what that one act includes for creation is contingent. This preserves CCC 296–298, which emphasizes creation is a free gift, not a forced emanation.

4. Unified Will, Distinct Outcomes

The Church insists that God’s will–being one with His essence–does not fragment into “parts” that might introduce necessity for all possible outcomes. The one divine will can freely choose a contingent universe without diminishing divine simplicity or contradicting the principle of indiscernibility. What remains “indiscernible” (and thus identical) is God’s will and God’s essence, not the created effect and God’s essence.



Hence, even while accepting the indiscernibility of identicals, Catholic theology maintains that God’s necessary self-identity does not render creation necessary. The difference between the divine act in itself and its free, contingent effect in creation ensures that God’s being is necessary, yet the cosmos remains a gratuitous gift of divine freedom.

(see #18, #20)