A Computationally Assisted Reconstruction of an Ontological Argument in Spinoza’s The Ethics

Jack K. Horner 1
  • 1 , Lawrence, United States of America


The comments accompanying Proposition (Prop.) 11 (“God ... necessarily exists”) in Part I of Spinoza’s The Ethics contain sketches of what appear to be at least three more or less distinct ontological arguments. The first of these is problematic even on its own terms. More is true: even the proposition “God exists” (GE), a consequence of Prop. 11, cannot be derived from the definitions and axioms of Part I (the “DAPI”) of The Ethics; thus, Prop. 11 cannot be derived from the DAPI, either. To prove these claims, I use an automated deduction system (ADS) to show that Prop. 11 is independent of the DAPI. I then augment the DAPI with some auxiliary assumptions I believe Spinoza would accept and that sustain an automated derivation of (GE). The results illustrate how an ADS can facilitate the analysis of arguments and yield an apparently novel argument cast in the style of Spinoza.

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