Occamism

Occamism (or Ockhamism) is the philosophical and theological teaching developed by William of Ockham (1285–1347) and his disciples, which had widespread currency in the fourteenth century.
Occamism differed from the other Scholastic schools on two major points: first, Occamism strongly argued position that only individuals exist, rather than supra-individual metaphysical universals, essences, or forms, and that universals are the products of abstraction from individuals by the human mind and have no extra-mental existence. Second, Occamism denied the real existence of metaphysical universals and advocated the reduction of ontology.
Content and method.
Occamism questions the physical and Aristotelian metaphysics and, in particular, insists the only reality of individuals accessible to knowledge intuitive. The universals, which exist only in the mind, have no correspondence with reality and are mere signs that symbolize a multiplicity of individuals. The further one goes from experience and generalizes, the more one imagines the constitution of the universal expressed by names. It is therefore necessary to revise the logical structures of discourse and language, taking care to separate the sign from the signified thing. Criticism of the concept of cause and substance, especially by the Occamistic Nicholas of Autrecourt, reduces the sciences to an immediate and intuitive way of knowing.
The Occamists using the Nominalist method separate theology from Aristotelian foundations, making them lose any possibility of presenting themselves as science, and reducing confidence in the power of reason applied to the demonstrations of God's existence and the immortality of the soul. They support God's absolute power that explains the contingency of creatures and the laws of nature. Divine omnipotence also includes the case that God can also comprehend a nonexistent object: an anticipation of the "deceptive God" 
a theme used by Descartes in solving the certainty of the cogito ergo sum.
Occamism had a wide influence in the period between the fourteenth and seventeenth centuries, contributing to the progressive dissolution of Scholastic Aristotelianism