This article will examine the reliability of George Berkeley's metaphysical theory of idealism. Berkeley's idealism holds that reality is made real by what the mind perceives and that what we perceive as material is actually a set of immaterial sensations. Idealism is defined as the view “that only mental entities exist, therefore physical things exist only in the sense that they are perceived” (“Idealism”). Berkeley's argument about subjective idealism is the view that reality consists of one's mind and its ideas, while objective idealism further states that a supreme mind produces ideas in the physical world that do not depend on the existence of human minds (Velasquez 146). Without objective idealism, one may suffer solipsism, which is the belief that only one's self and experiences of the world are real and that everything else does not exist (“solipsism”). The opposite idealism is the metaphysical view of materialism which holds that only physical things exist ("materialism"). This article will begin by examining George Berkeley's views on subjective and objective idealism and how they apply to reality. Next, the criticisms made and supported by Aristotle and Thomas Hobbes against both views of idealism will be discussed. However, these arguments fail to adequately examine Berkeley's idealism, causing criticism to be based on misinformation. Although the criticisms pose potential flaws, Berkeley's idealism continues to be an important discussion in the metaphysical debate. Through the vision of subjective idealism, objects become real when a mind perceives their qualities. Berkeley argues that when an object is perceived, its qualities are the perceived parts because the qualities are compatible with the senses; sight, smell, touch, taste and soul… middle of paper… the ultimate mind and its perceptions exist if it cannot perceive itself. Works Cited Aristotle, R.P. Hardie, and R.K. Gaye. Physics. Adelaide: Adelaide University Library, 2000. Print.Berkeley, George and George H. Thomas. Philosophical commentaries. New York: Garland Pub., 1989. Print.Berkeley, George. Treatise on the Principles of Human Knowledge. Dublin: University of Oxford, 1710. Print.Downing, Lisa. "George Berkeley." Stanford University. Stanford University, September 10, 2004. Web. April 23, 2014. Hobbes, Thomas, and Rod Hay. Leviathan. Hamilton: McMaster University, 1999. Print."Philosophical Dictionary." Philosophical dictionary. Np, nd Web. June 2, 2014. Velasquez, Manuel. Philosophy: a text with readings. Boston: Clark Baxter, 2011. Print.