Abstractionism is the theory that the mind obtains some or all of its concepts by abstracting them from concepts it already has, or from experience.[1] One may, for example, abstract 'green' from a set of experiences which involve green along with other properties. Also, for example, one may abstract a generic concept like 'vegetable' from the already possessed concepts of its instances (carrot, broccoli, onion, etc.) This view was criticized by George Berkeley[2] and Peter Geach.[1]