  As concerns human psychology, Gassendi offers a materialist (hence ultimately atomist) account of the passions as a function of the vegetative soul, including desire and fear, and motivating pleasure and pain (O II 474f, 495f); these are ultimately governed, however, by the rational and immaterial soul. There are, broadly, any number of cognitive faculties and attributes that may be built out of or be produced by atoms, Gassendi suggests, countering Lactantius's complaint that the ‘senses, thought, memory, the mind, genius, [or] reason’ cannot so be constructed. As with the passions, though, there are limits.  A viable atomist story can be told of sensory phenomena and idea-formation though not reason and its allied phenomena (O I 282b).  Yet there is clearly some grey area, as memory in particular seems open to a purely materialist account. Memory loss results from a physical change in the brain resulting from undernourishment; folds in brain matter preserve the physical embodiment of memory, but a deficiency in nutrition leads to the deterioration of those folds (O II 406b-407b; a similar Cartesian view appears in the Treatise on Man (AT XI 177-178)).