“ This view was an extreme development of the Aristotelian doctrine that all reality is individual, and that universals have existence only in individual objects; and it was called forth by the extreme Neo-Platonism of Erigena, who maintained that universals have an existence prior to particulars and individuals, and that the process of creation is only the progressive, logical differentiation of the universal. ”

“ The Arabian philosophers, and especially Avicenna (q.v.) , succeeded in mediating between nominalism and realism by maintaining that universals are before individuals (realism) in the mind of God, in individuals (Aristotelianism) as their developed essence, and after individuals (nominalism) in human minds (conceptualism) . This was the view adopted by Thomas Aquinas (q.v.) in his system and so incorporated in the received philosophy of the Roman Church. Nominalism received its last strong support in the teaching of William of Occam (q.v.) ”