Oil painting did to appearances what capital did to social relations. It reduced everything to the equality of objects. Everything became exchangeable because everything became a commodity. All reality was mechanically measured by its materiality. The soul, thanks to the Cartesian system, was saved in a category apart. A painting could speak to the soul - by way of what it referred to, but never by the way it envisaged. Oil painting conveyed a vision of total exteriority.

— Ways of Seeing by John Berger, et al (Page 87)