At the threshold between visibility and invisibility, earthly life and spiritual vistas, here’s Rilke in the famous 1925 letter to his Polish translator, Witold Von Hulewicz, about the material transformation of object-things into invisible form and, then back again, into new materializations. At the very end of the letter, Rilke will sound a little like Deleuze writing about the virtual and becoming machine.
“Nature, the things we move among and use, are provisional and perishable, but they are. For as long as we are here, our possession and our friendship, sharers in our trouble and our happiness, just as they were once the confidants of our ancestors. Therefore it is crucial not only that we not corrupt and degrade what constitutes the here and now, but precisely because of this provisionality it shares with us, that these appearances and objects be comprehended by us in a most fervent understanding and transformed. Transformed? Yes, for our task is to stamp this provisional, perishing earth into ourselves so deeply, so painfully and passionately, that its being may rise again, “invisibly,” in us. We are the bees of the Invisible. Nous buttinons éperdument le miel du visible, pour l’accumuler dans la grande ruche d’or de l’Invisible [We wildly gather the honey of the invisible, in order to store in the great golden hive of the Invisible.] The Elegies show us at this work, this work of the continual conversion of the dear visible and tangible into the invisible vibration and agitation of our nature, which introduces new vibration-numbers into the vibration-spheres of the universe. (For since the various material in the cosmos are only different vibration-rates, we are preparing in this way, not only intensities of a spiritual kind, but –who knows?—new bodies, metals, nebulae, and constellations).”
(I found this in the notes to Rainer Maria Rilke, Duino Elegies, translated by Edward Snow, North Point Press, p.70)