Univocity of being is the idea that words describing the properties of God mean the same thing as when they apply to people or things, even if God is vastly different in kind.
In medieval disputes over the nature of God, many theologians and philosophers (such as Thomas Aquinas) held that when one says that "God is good", God's goodness is only analogous to human goodness. John Duns Scotus argued to the contrary that when one says that "God is good", the goodness in question is exactly the same sort of goodness that is meant when one says "Jane is good". That is, God only differs from us in degree, and properties such as goodness, power, reason, and so forth are "univocally" applied, regardless of whether one is talking about God, a man, or a flea.
Gilles Deleuze borrowed the doctrine of ontological univocity from Scotus. He claimed that being is univocal, i.e., that all of its senses are affirmed in one voice. Deleuze adapts the doctrine of univocity to claim that being is, univocally, difference. "With univocity, however, it is not the differences which are and must be: it is being which is Difference, in the sense that it is said of difference. Moreover, it is not we who are univocal in a Being which is not; it is we and our individuality which remains equivocal in and for a univocal Being."
Deleuze at once echoes and inverts Spinoza, who maintained that everything that exists is a modification of the one substance, God or Nature. He claims that it is the organizing principle of the Dutchman's philosophy, despite the absence of the term from any of Spinoza's works. For Deleuze, there is no one substance, only an always-differentiating process, an origami cosmos, always folding, unfolding, refolding. Deleuze and Guattari summarize this ontology in the paradoxical formula "pluralism = monism".