Testament. is used 119 times and is used 161 times, usually with the meaning 'power/ability' and 'act/work', respectively. Essence-energies debate in medieval Christian theology In Eastern Orthodox Christianity, St Gregory Palamas wrote about the "energies" (actualities; singular in Greek, or in Latin) of God in contrast to God's "essence" (). These are two distinct types of existence, with God's energy being the type of existence which people can perceive, while the essence of God is outside of normal existence or non-existence or human understanding, i.e. transcendental, in that it is not caused or created by anything else. Palamas gave this explanation as part of his defense of the Eastern Orthodox ascetic practice of hesychasm. Palamism became a standard part of Orthodox dogma after 1351. In contrast, the position of Western Medieval (or Catholic) Christianity, can be found for example in the philosophy of Thomas Aquinas, who relied on Aristotle's concept of entelechy, when he defined God as , pure act, actuality unmixed with potentiality. The existence of a truly distinct essence of God which is not actuality, is not generally accepted in Catholic theology. Influence on modal logic The notion of possibility was greatly analyzed by medieval and modern philosophers. Aristotle's logical work in this area is considered by some to be an anticipation of modal logic and its treatment of potentiality and time. Indeed, many philosophical interpretations of possibility are related to a famous passage on Aristotle's On Interpretation, concerning the truth of the statement: "There will be a sea battle tomorrow". Contemporary philosophy regards possibility, as studied by modal metaphysics, to be an aspect of modal logic. Modal logic as a named subject owes much to the writings of the Scholastics, in particular William of Ockham and John Duns Scotus, who reasoned informally in a modal manner, mainly to analyze statements about essence and accident. Influence on early modern physics Aristotle's metaphysics, his account of nature and causality, was for the most part rejected by the early modern philosophers. Francis Bacon in his Novum Organon in one explanation of the case for rejecting the concept of a formal cause or "nature" for each type of thing, argued for example that philosophers must still look for formal causes but only in the sense of "simple natures" such as colour, and weight, which exist in many gradations and modes in very different types of individual bodies. In the works of