In the 18th-century, perhaps for the first time in human history, thinking men confronted the prospect of death and personal annihilation without illusion. In this striking portrait of 1777 by the Danish artist Juel Jens the naturalist Charles Bonnet is captured in just such a moment of solemn reflection; Bonnet reports that Jens depicted him "mediating on the future restoration and perfection of living beings". The Bible before him is open at First Corinthians 15:36: "That which thou sowest is not quickened, except it die - O death, where is thy sting? O grave, where is thy victory?". The inscription reads "CHARLES BONNET, born in Geneva, 13th March 1720. FUTURI SPES VIRTUTEM ALIT ("The hope of the future sustains virtue")
As Fernando Vidal notes in his study of 2003, the question of future resurrection, was tinged for Bonnet by particular sadness and hope at this time due to the death or impending death of his friend Albrecht von Haller. On 18th May 1777, Haller lamented the loss of a lifetime's worth of ideas: "Alas, my brain, which soon will be a mere heap of dust! I can hardly endure the thought that so many ideas accumulated during a long life should be lost as a child's dreams would be." Was it conceivable, Bonnet asked, that death could "forever deprive a Leibniz, a Newton, or a Haller of the precious fruits of their intelligence and experience?" (Quoted Vidal, p.88-9, nt 84 and nt 85)
Bonnet's own beliefs were uneasily poised between materialism and Christian faith. In his view human beings were "mixed beings" in which body and soul were inextricably bound together: personal identity depended on memory and was based in the brain. Inspired by Leibniz, he speculated that there existed within the brain an indestructible organ, a ‘little ethereal machine’, which preserved the soul after death and might act as the seed for a future reconstituted body. This notion placed the idea of bodily resurrection at the centre of Bonnet's philosophy and furnished him, as he saw it, with a rational confirmation of Christian doctrine.
https://www.google.co.uk/books/edition/Contemplation_de_la_nature/9iiYa72FoloC?hl=en&gbpv=1&pg=PA87&printsec=frontcover
https://www.academia.edu/6811077/Extraordinary_bodies_and_the_physicotheological_imagination
