Reason (philosophy)
Reason in philosophy refers to the cognitive ability to think logically, rationalize, and understand concepts through logical processes. The term itself originates from the Latin word "ratio," which means to consider. Throughout history, influential philosophers such as Aristotle, Plato, Immanuel Kant, and René Descartes have explored the significance of reason in establishing truth and understanding human nature. Reason is often seen as a tool for organizing perceptions and knowledge, enabling individuals to navigate complex experiences and ethical dilemmas.
Philosophical discussions about reason have produced various perspectives: some view it as a means to elevate human understanding above mere instinct, while others criticize its use as a tool for argumentation. Reasoning can be categorized into three types—inductive, deductive, and abductive—each with its own strengths and weaknesses in forming conclusions. Additionally, the evolution of reasoning has been studied in developmental psychology, revealing that logical reasoning begins to form in children around age seven.
In contemporary debates, the argumentative theory posits that reason may have developed primarily for the purpose of persuasive debate. Despite differing views, reason remains a central focus in philosophy, psychology, and science, underpinning the quest for knowledge and truth. This ongoing exploration reflects a rich tapestry of thought that highlights the complexity of human cognition and its implications for understanding the world.
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Reason (philosophy)
Reason is the ability to think, rationalize, and understand using the process of logic. The word reason is derived from the Latin ratio, which comes from the verb meaning consider. The role of reason in confirming truth has been studied by figures such as philosophers Aristotle, Plato, Immanuel Kant, and Rene Descartes.
Reason is a tool of understanding and comprehension. It assists in identifying and cataloging perceptions, experiences, and concepts into a base knowledge. Reason is a thought process that requires clear-headedness and emotionless consideration of facts, logic, and deduction. In a philosophic sense, reason is absolute. Some philosophers claim reason is no more than a tool to win arguments, while others say it elevates humans above their animalistic nature.
Scientific researchers have studied human and animal development to determine if and when the process of reasoning forms. Evidence shows that reasoning does not exist in most animals or preverbal children. Infants are not born with the ability to logically reason. As they grow and their brains develop, children begin to interact and adjust to the world around them, eventually being able to develop a form of logic as early as age seven.
In the scientific process, reason is a valuable tool in determining hypotheses and theories as a way to discover the truth. Psychologists categorize this form of scientific reasoning in three ways.
Inductive reasoning takes specific observations, discerns patterns, and makes a broad generalization based on the evidence. For example: Felix is a cat. Felix is brown. All cats are brown. While this form of reasoning can be inaccurate, it can be used to develop a hypothesis for further testing.
Deductive reasoning takes a general statement or hypothesis, logically examines the outcomes to eliminate false statements, and arrives at a specific conclusion. The ultimate truth of the conclusion depends on the reliability of the original statement. For example: All planets orbit the sun. Jupiter is a planet. Jupiter orbits the sun. However, if the initial hypothesis was inaccurate, the conclusion would be as well. All planets have rings. Mars is a planet. Mars has rings.
Abductive reasoning takes incomplete observations and uses logic to arrive at the most likely outcome. Because it relies on incomplete information, abductive reasoning may require an educated guess during the process. This can lead to an inaccurate conclusion, but it is useful in producing theories for further testing.
Philosophers and Reason
In the fourth century BCE, Greek philosopher Aristotle wrote there are five intellectual virtues: scientific knowledge, intuition, wisdom, art or technical skill, and prudence. These virtues require either contemplative reasoning or calculative reasoning. Prudence is the intellectual skill that allows man to reason through ethical concerns. Aristotle argued that man’s rational soul enables humans to rise above animals through thought and reasoning, and that the purpose of life was to develop and exercise that rational soul—honing one’s humanity through reason.
Aristotle strove to find the first principles or starting points of each inquiry he made. He argued this was the path to knowledge, and the highest achievement a man could attain was to live consistently in accordance with reason. Greek philosopher Plato, who was Aristotle’s teacher, suggested in his Republic, a dialogue on society and justice, that the soul is composed of the logical, the spirited or courageous, and the desire to satisfy bodily needs. Although the logical was the smallest element, it determined the definition of truth, and that a person is considered just only if they are ruled by logic or reason. A student of Plato, Plotinus, argued that even the cosmos had a soul. This soul held the souls of humans that embraced reason and logic. Some later monotheistic religions built upon this theory, believing that a single Creator was the seat of reason for the entire universe.
Empiricist belief—the idea that knowledge and reason derive from sensory experiences—considers these experiences as the starting point of reason, and that memories, emotions, and ideas are non-reason. By relying on their senses and channeling those perceptions into concepts through rational evaluation, humans apply themselves to reasonable thinking. The classical philosophical definition of reasoning holds that reason is used to advance understanding and knowledge in the search for truth.
Rene Descartes, a seventeenth century French philosopher, famously stated, "I think, therefore I am," which was a revolutionary concept stating that human beings exist because they are thinking organisms. British philosopher Thomas Hobbes developed the idea of calculative reason that argued memories and senses are responsible for acquiring knowledge.
A follower of Descartes, Scottish philosopher David Hume, argued in his 1739 work, A Treatise on Human Nature, that passion and emotion rule human behavior, not reason. He stated, "Reason is and ought to only be the slave of the passions." German philosopher Immanuel Kant disagreed in his The Critique of Pure Reason, writing in 1781 that reason possesses a clearly defined structure and the only things mankind can truly understand are empirical concepts that can be proven, such as mathematics or science.
Modern Debate
In the twenty-first century, French social scientists developed the argumentative theory of reasoning. The theory states that humans created reason and rationality solely for the purpose of winning a debate or argument. Most twenty-first century philosophy and psychology adhere to the Cartesian idea of reasoning—named after Descartes. This concept views the role of reason as a method of eliminating or reducing incorrect beliefs and thoughts in order to uncover a reliable knowledge base. The founders of the argumentative theory believe the Cartesian model is fallible and without questioning and exploring other possibilities, progress in the field cannot be made.
Bibliography
Aristotle. "The Nicomachean Ethics." Liberty Fund. Liberty Fund, 2015. Web. 21 Sept. 2015. <http://oll.libertyfund.org/titles/903>.
Bradford, Alina. "Deductive Reasoning vs. Inductive Reasoning," Livescience. Purch, 23 Mar. 2015. Web. 5 Oct. 2015. <http://www.livescience.com/21569-deduction-vs-induction.html>.
McCormick, Matt. "Immanuel Kant: Metaphysics," IEP. Internet Encyclopedia of Philosophy and Its Authors, n.d. Web. 21 Sept. 2015. <http://www.iep.utm.edu/kantmeta/#H7>.
Mercier, Hugo, and Dan Sperber. "Why Do Humans Reason? Arguments for an Argumentative Theory." Behavioral and Brain Sciences 34 (2011): 57–111. PDF file. <http://www.dan.sperber.fr/wp-content/uploads/2009/10/MercierSperberWhydohumansreason.pdf>.
Moore, Edward. "Plotinus." IEP. Internet Encyclopedia of Philosophy and Its Authors, n.d. Web. 21 Sept. 2015. <http://www.iep.utm.edu/plotinus/>.
"Piaget’s Stages of Cognitive Development." Boundless. Boundless Psychology, 20 Aug. 2015. Web. 2 Oct. 2015. <https://www.boundless.com/psychology/textbooks/boundless-psychology-textbook/human-development-14/theories-of-human-development-70/piaget-s-stages-of-cognitive-development-270-12805/>.
"Plato." Philosophy Basics. Luke Mastin, 2008. Web. 21 Sept. 2015. <http://www.philosophybasics.com/philosophers‗plato.html>.