Could it be the case that all of us as individual human subjects stand to one another as Caeiro stands to Reis and Reis to Campos: just as they are the multiple heteronyms of one and the same subject, Fernando Pessoa, so too we are all heteronyms of one and the same subject, a single cosmic subject? There is a famous line in the Chāndogya Upaniṣad which might be interpreted as saying something of the sort—tat tvam asi: you are that, that single cosmic subject, brahman. For the eighth-century Vedāntic philosopher Śaṅkara, whose reading of the Upaniṣads would much later establish itself in the popular imagination, the similarity is further reinforced because he provides a context of phenomenological simulation similar to dreaming and imagining, namely, māyā, ‘cosmic illusion’. Let me call the view that individual human subjects are heteronyms of a single cosmic self ‘heteronymic cosmopsychism’. Heteronymic cosmopsychism is different from the comparatively more common variety of cosmopsychism according to which the grounding relation between the single cosmic self and the multiplicity of individual selves is mereological, not heteronymic. Heteronymic cosmopsychism agrees with priority monism in rejecting a monistic existence thesis, differing from it only as to the nature of the grounding relation, sidestepping the problems that bedevil priority cosmopsychism because its grounding relation is not one of decomposition.