This oil on oak panel painting, a rapid and expressive sketch by Frans Hals from 1647-1648, captures the likeness of René Descartes with lively brushstrokes. The raw quality of the medium on the wood support gives the portrait an immediate, almost informal feel. Notably, the surface bears zigzag scratches, historical damage believed to be a reaction to Descartes' revolutionary and sometimes controversial philosophical and mathematical ideas. This small work, likely a preparatory study for an engraving or a larger portrait, offers a glimpse into the mind of a pivotal thinker. It would make a striking and thought-provoking addition to a home office or a minimalist living space.