“The Upanishads teach the unity of the Supreme Being, and the worship of one God alone.”
— Ram Mohan Roy[commonly attributed] Theme of Roy's translations of the Upanishads and his prefaces; wording a summary

Commentary

This summary captures Ram Mohan Roy's presentation of the Upanishads as texts teaching the worship of one supreme being, a reading that was central to his claim that Vedanta supports monotheism. His translations, published in English and Bengali in the 1810s and 1820s, were prefaced with arguments that aimed to show the coherence of the scriptures with reason. Sophia Dobson Collet's biography describes the translations as the foundation of his effort to recover an uncorrupted Hindu tradition. David Kopf, in The Brahmo Samaj and the Shaping of the Modern Indian Mind (1979), shows how Roy's reading of the Upanishads differed from both orthodox polytheism and Christian critics' view of Hinduism as idolatrous. Later Brahmo writers adopted Roy's reading, sometimes in modified forms. The wording here summarises his position, and the prefaces to the translations should be consulted for the author's own formulations.