Does the theory of theistic evolution violate the principle of sufficient reason?

1. What the parties mean: PSR and the family of theistic‑evolution views

The Principle of Sufficient Reason, in its standard philosophical formulation, insists that everything has a sufficient reason either extrinsically or intrinsically—a demanding metaphysical claim historically associated with Leibniz and later defenders of classical theism ^[4]; by contrast, “theistic evolution” is a wide family of positions ranging from those who see God as setting initial conditions and natural laws to those who endorse intermittent divine direction or even ongoing providential guidance throughout evolutionary history ^{[1] [2] [3]}.

2. How critics frame the conflict: continual intervention and economy of explanation

Some critics argue that certain versions of theistic evolution do violate PSR (or related principles such as the “principle of economy”) by positing repeated divine interventions or miracles to account for evolutionary transitions without supplying independent sufficient reasons for each intervention; this charge appears explicitly in attacks that claim continual divine input would multiply causes and thereby breach economy or sufficiency standards ^{[5] [6]}.

3. How defenders respond: God as grounding of sufficient reason or non‑interventionist cause

Defenders reply on two fronts: metaphysically, classical theists can treat God not as one cause among many but as the ultimate grounding of reasons, so divine action does not create an explanatory deficit but supplies the deepest sufficient reason for contingent processes (this is a standard move in PSR‑friendly theism) ^[4]; methodologically, many theistic evolutionists affirm that natural mechanisms (mutation, selection and other processes) are sufficient to explain biological form at the material level while reserving room for God as metaphysical ground or as non‑detectable sovereign cause, a stance that avoids frequent ad hoc interventions and therefore sidesteps the critics’ charge ^{[1] [3]}.

4. Middle positions and philosophical stakes: sufficiency vs. explanatory priority

Philosophers and theologians split on whether the sufficiency of natural explanations in evolutionary biology (the claim many theistic evolutionists accept) undercuts the need for divine explanations in science by Occam’s razor—a move critics like Lawrence Krauss and skeptical naturalists endorse—or whether God’s role should be understood at another explanatory level (grounding metaphysics, teleology, or the originary establishment of laws) that PSR requires rather than contradicts ^{[1] [7] [8]}. The dispute therefore often reduces to a question of explanatory priority and levels: if God is posited as an ultimate sufficient reason for why the universe is such that evolution occurs, PSR can be preserved; if God is invoked as a recurrent plug for unexplained micro‑steps, critics allege a PSR violation ^{[8] [5]}.

5. Judgment and implications: no single verdict, only conditional assessment

The strongest, most defensible conclusion is conditional: theistic evolution per se does not automatically violate the PSR; some articulations—those positing frequent, unexplained divine tinkering to account for specific evolutionary novelties—lean into the very problems critics identify and risk violating principles of sufficiency and economy ^{[5] [6]}, whereas accounts that place God as the metaphysical ground of contingent reality or as the providential author of initial laws and conditions can be presented as PSR‑consistent while allowing evolutionary mechanisms to do the empirical explanatory work ^{[4] [3]}.