Spinoza’s expansive necessitarianism

This paper argues that Spinoza is best understood as a necessitarian of a particularly radical kind: one who holds not only that the possible and the actual are coextensive, but further that the domain of actuality is as broad as the domain of conceivability. I call this view ‘expansive necessitarianism’ and contrast it with the more familiar ‘restrictive necessitarianism’. However, while EIp16 and related texts support a plenitudinous ontology, plenitude alone does not explain why the system of finite modes must take on the unique arrangement that it does. In this paper, I develop three Spinozistic constraints that sharply narrow the apparent possibility space: (i) the requirement that the series of finite modes is ontologically exhaustive, (ii) the infinite complexity of the laws of nature, and (iii) the universal causal integration entailed by Spinoza’s denial of the possibility of a physical vacuum. Together, these constraints eliminate all but one possible arrangement of finite modes, and Spinoza’s necessitarianism emerges as a distinctive and hitherto underappreciated metaphysics of modality.