The Immutability of God is an attribute that "God is unchanging in his character, will, and covenant promises." The Westminster Shorter Catechism says that "[God] is a spirit, whose being, wisdom, power, holiness, justice, goodness, and truth are infinite, eternal, and unchangeable." Those things do not change. A number of Scriptures attest to this idea (such as Num. 23:19; 1 Sam. 15:29; Ps. 102:26; Mal. 3:6; 2 Tim. 2:13; Heb. 6:17–18; Jam. 1:17) God's immutability defines all God's other attributes: God is immutably wise, merciful, good, and gracious. The same may be said about God's knowledge: God is almighty/omnipotent (having all power), God is omnipresent (present everywhere), God is omniscient (knows everything), eternally and immutably so. Infiniteness and immutability in God are mutually supportive and imply each other. An infinite and changing God is inconceivable; indeed, it is a contradiction in definition. Ancient Roots The Old Testament includes several verses that support God's immutability. This includes verses such as "I, the Lord, do not change." (Malachi 3:6, NIV) or the more limited "He who is the Glory of Israel does not lie or change his mind; for he is not a human being, that he should change his mind.” (1 Samuel 15:29, NIV), implying that God does not change his mind. Likewise, Ancient Greek philosophers advocated the view that God does not change. In his Republic, Plato dismisses the idea found in Greek myth and poetry that the gods can change in any way. Rather, Plato argues, God is perfect and cannot and does not change. For if a god is already the best possible in these respects, a god cannot change for the better. But being perfect includes being immune to change for the worse — too powerful to have it imposed without permission and too good to permit it. Thus a god cannot improve or deteriorate, making any change within God impossible. Following Plato, the idea that God is perfect and cannot change became widely accepted among philosophers. Aristotle also accepted the idea that God was perfect and unchanging and it became a central point of his philosophy, which would influence philosophers and theologians throughout the Middle Ages. Philo, who combined Greek philosophical thought with Biblical exegesis in his works, argues in On the Unchangeableness of God that God is perfect, beyond all space and time and creator of both, and is therefore not subject to any emotions