William of Ockham employs his powerful logical faculty to elaborate an influential theology in his Quodlibeta septem (“Seven Miscellaneous Questions”) and his Summa totius logicae (“Sum of All Logic”).

Adopting a nominalist solution to the problem of universals, William maintains that all existing things are individuals and that universality exists only in concepts or names.

It logically follows, therefore, that God, unhampered by any universal essences, is free to create every individual unconnected with every other, and that subsequent causal connections among such individuals are unnecessary.

Accepting the Aristotelian dictum that science is demonstration based on certain, secure premises, William rejects the Thomistic view that theology is a proper science and therefore rejects rational demonstrations of God's existence, of divine attributes, and of the immortality of the soul.

He counters the philosophical explanations of others with the logical principle of parsimony, sometimes called Occam's razor (but used by some scholastic philosophers before him): "A plurality (of reasons) should not be posited without necessity."

Ockham, whose nominalist views in law and ethics lead him to voluntarism and emphasis on the divine command, concludes that the ultimate source of value and obligation lies not in any "natures" of things but in the free will of God.

He views the rightness or wrongness of human acts as a function of their being commanded or forbidden by divine authority.