There are likely as many variants of pantheism as there are of classical theism. Pantheists differ with one another over their fundamental ontology and what features of reality provide the sort of unity and complexity necessary to ground our theological discourse. For instance, some pantheists are substance monists, taking space-time to be the one substance of which everything else is but a mode or collection of modes pinned to the one substance.

Other pantheists reject substance monism, seeking the unity in some other feature of the universe. Still further, some pantheists regard pantheism as a non-theistic conception of divinity while others regard it as theistic and even think it is sufficient for grounding a conception of God as personal. Similarly, panentheists differ over the nature of the relationship God bears to the universe. For instance, while some panentheists talk of emergent properties or emergent substances that are in some way ontologically dependent upon the universe, others eschew such a framework in favor of taking God to be constituted by the universe.

On such a view, constitution is assumed to be a different relationship from identity. Hence, if Y constitutes X, X is not identical with Y. X and Y have different persistence conditions. The universe constitutes God when it displays a level of complexity and unity that is sufficient for God to exist. Still other panentheists analogize the relationship between God and the universe to the relationship between mind and body on non-reductive physicalism.