These are two very different things, and carefully to be distinguished; it being one thing to perceive and know the idea of white or black, and quite another to examine what kind of particles they must be, and how ranged in the superficies, to make any object appear white or black.
Horiek bi gauza oso ezberdinak dira eta kontu handiz bereizi beharrekoak, gauza bat baita zuri edo beltzaren ideia hauteman eta ezagutzea, eta beste bat, oso diferentea, azaleretan nolako partikulak egon behar duten eta nola ordenatuta aztertzea, edozein objektu zuri edo beltz ager dadin.