Simple ideas, why undefinable, further explained. The contrary shown in complex ideas, by instances of a statue and rainbow. Colours indefinable to the born-blind. Complex ideas definable only when the simple ideas of which they consist have been got from experience. Names of simple ideas of less doubtful meaning than those of mixed modes and substances.
Simple ideas have few ascents in linea praedicamentali.
Names of simple ideas not arbitrary, but perfectly taken from the existence of things.