Lesson 1: Introduction to Logic PDF

Lesson 1: Introduction to Logic +-----------------------+-----------------------+-----------------------+ | | Logic as a Branch of | -Logic is one of the | | | Philosophy | branches of | | |...

Lesson 1: Introduction to Logic +-----------------------+-----------------------+-----------------------+ | | Logic as a Branch of | -Logic is one of the | | | Philosophy | branches of | | | | philosophy. It is | | | | considered the most | | | | fundamental because | | | | it provides a person | | | | with the rational | | | | capability to engage | | | | in a further study of | | | | philosophy. | | | | | | | | -Dating back to | | | | Aristotle, logic is | | | | one of the oldest | | | | intellectual | | | | disciplines in human | | | | history. It has been | | | | studied through the | | | | centuries. It is | | | | still a subject of | | | | active investigation | | | | today. | +=======================+=======================+=======================+ | | Meaning of Logic | -Logic is broadly | | | | defined as the | | | | science and art of | | | | correct thinking and | | | | reasoning. | | | | | | | | -The term "logic" | | | | comes from the Greek | | | | word "logikos" which | | | | means ordered, | | | | systematized, or | | | | intelligible. | | | | | | | | -Logic is the study | | | | of methods of | | | | evaluating whether | | | | the premises of an | | | | argument adequately | | | | supports its | | | | conclusion. | | | | | | | | -Logic is the study | | | | of the methods and | | | | principles used to | | | | distinguish correct | | | | from incorrect | | | | reasoning. | | | | | | | | -Logic is the field | | | | of study concerned | | | | with analyzing | | | | arguments and | | | | appraising their | | | | correctness or | | | | incorrectness. | | | | | | | | -Logic is the | | | | organized body of | | | | knowledge (science) | | | | that evaluates | | | | arguments. | +-----------------------+-----------------------+-----------------------+ | | Logic as a Science | -Logic is considered | | | and Art | a science for three | | | | major reasons: 1) it | | | | is a body of | | | | knowledge, 2) this | | | | body of knowledge is | | | | arranged in a | | | | systematic manner, | | | | and 3) it is | | | | objective and | | | | possesses general | | | | principles of | | | | argumentation and | | | | proof which can be | | | | formulated precisely | | | | and communicated to | | | | others. | | | | | | | | -Logic is considered | | | | an art because with | | | | the knowledge of the | | | | principles of correct | | | | thinking and | | | | reasoning, one can | | | | think and reason | | | | easily, | | | | spontaneously, and | | | | correctly. As an art, | | | | logic equips the mind | | | | with the capability | | | | to think right and | | | | without much effort. | +-----------------------+-----------------------+-----------------------+ | | Logic and Reason | -Logic deals with | | | | laws and rules. We | | | | submit to these laws | | | | and rules because we | | | | clearly see that they | | | | must be as they are. | | | | The mere reality of | | | | these laws and rules | | | | make us submit. | | | | However, logic does | | | | not require blind | | | | memorizing or a | | | | merely mechanical | | | | application of the | | | | laws and rules. A | | | | student of logic | | | | should not be | | | | satisfied with | | | | anything short of | | | | understanding the | | | | laws and rules. | | | | | | | | -To some extent, all | | | | of us are logicians | | | | by nature. We must | | | | not suppose that we | | | | know nothing at all | | | | about logic before we | | | | have formally studied | | | | it inside the | | | | classroom. Simply | | | | because we are | | | | rational beings, we | | | | spontaneously know | | | | the general laws of | | | | correct thinking and | | | | necessarily subject | | | | to them. The law of | | | | gravity was in effect | | | | before Newton | | | | formulated it. Human | | | | beings employ a | | | | certain way of | | | | thinking before | | | | Aristotle wrote the | | | | rules and laws. | +-----------------------+-----------------------+-----------------------+ | | Logic and Critical | -In this age of fake | | | Thinking | news, logic and | | | | critical thinking | | | | becomes all the more | | | | relevant and | | | | necessary. They are | | | | tools that allow us | | | | to navigate the flow | | | | of information, to | | | | sort out the good and | | | | the bad, to find | | | | patterns, to combine | | | | apparently unrelated | | | | bits, and to figure | | | | out how information | | | | can enrich our lives | | | | and help us manage | | | | our practical | | | | affairs. | | | | | | | | -Logic and critical | | | | thinking are not new | | | | to us. We could | | | | hardly have come this | | | | far without them. | | | | Many of the most | | | | important logical | | | | principles are | | | | embedded in language, | | | | and you learn them | | | | when you learn how to | | | | use such terms as | | | | ***and***, ***or***, | | | | and ***not***. We use | | | | logic and critical | | | | thinking when we | | | | organize materials to | | | | write term papers, | | | | try to persuade | | | | others to share your | | | | beliefs, convince | | | | friends to see one | | | | movie rather than the | | | | other, and defend | | | | your words and | | | | actions against | | | | critics. | | | | | | | | -Critical thinking | | | | refers to many | | | | different activities | | | | and abilities. The | | | | following list | | | | includes some of the | | | | important ones: | | | | | | | | 1\. analyzing the | | | | meaning of | | | | information | | | | | | | | 2\. checking | | | | information for | | | | accuracy and | | | | completeness | | | | | | | | 3\. putting various | | | | pieces of | | | | information | | | | together in a | | | | | | | | coherent way | | | | | | | | 4\. comprehending | | | | instructions and | | | | advice | | | | | | | | 5\. following | | | | directions | | | | | | | | 6\. solving problems | | | | | | | | 7\. judging what | | | | information is | | | | relevant to an | | | | issue | | | | | | | | 8\. questioning | | | | matters that do not | | | | make sense | | | | | | | | 9\. making decisions | | | | and plans based on | | | | the best available | | | | | | | | information or | | | | evidence | +-----------------------+-----------------------+-----------------------+ | | Reasons for Studying | -We study logic to | | | Logic | develop methods and | | | | techniques that allow | | | | us to distinguish | | | | good arguments from | | | | bad. | | | | | | | | -We study logic to | | | | make sense when we | | | | criticize the | | | | arguments of others | | | | and when we advance | | | | arguments of our own. | | | | | | | | -Having the ability | | | | to reason in a | | | | particular way | | | | distinguishes humans | | | | from the rest of the | | | | animal kingdom. | | | | Learning the various | | | | techniques of logic | | | | improves and perfects | | | | the very reasoning | | | | ability that is so | | | | essential to our | | | | being human. | | | | | | | | -Studying logic will | | | | make explicit the | | | | rules of inference | | | | (reasoning) that are | | | | already part of your | | | | everyday life. | | | | | | | | -Whatever your | | | | college major is, a | | | | strong foundation in | | | | making good | | | | inferences or doing | | | | logic will improve | | | | your performance. | +-----------------------+-----------------------+-----------------------+ | | History of Logic | -The person who is | | | | generally credited as | | | | the father of logic | | | | is the ancient Greek | | | | philosopher Aristotle | | | | (384 -- 322 B.C.E.). | | | | Aristotle was the | | | | first to devise the | | | | systematic criteria | | | | for analyzing and | | | | evaluating arguments. | | | | | | | | -Aristotle's chief | | | | accomplishment is | | | | called syllogistic | | | | logic. It is a kind | | | | of logic in which the | | | | fundamental elements | | | | are terms, and | | | | arguments are | | | | evaluated as good or | | | | bad depending on how | | | | the terms are | | | | arranged in an | | | | argument. | | | | | | | | -Aristotle also | | | | deserves credit for | | | | originating modal | | | | logic. It is the kind | | | | of logic that | | | | involves such | | | | concepts as | | | | possibility, | | | | necessity, belief and | | | | doubt. In addition, | | | | Aristotle also | | | | catalogued several | | | | informal fallacies. | | | | | | | | -After the death of | | | | Aristotle, the Greek | | | | philosopher | | | | Chrysippus (280-206 | | | | B.C.E.) developed a | | | | logic in which the | | | | fundamental elements | | | | were whole | | | | propositions. | | | | Chrysippus treated | | | | every proposition as | | | | either true or false. | | | | He developed rules | | | | for determining the | | | | truth or falsity of | | | | compound propositions | | | | from the truth or | | | | falsity of their | | | | components. | | | | | | | | -For thirteen hundred | | | | years after the death | | | | of Chrysippus, | | | | relatively little | | | | work was done in | | | | logic. The physician | | | | Galen (C. E. 129-ca. | | | | 199) developed the | | | | theory of compound | | | | categorical | | | | syllogism, but for | | | | the most part | | | | philosophers confined | | | | themselves to writing | | | | commentaries on the | | | | works of Aristotle | | | | and Chrysippus. | | | | Boethius (ca. | | | | 480-524) is a | | | | noteworthy example. | | | | | | | | -The first major | | | | logician in the | | | | Middle Ages was Peter | | | | Abelard (1079-1142). | | | | Abelard reconstructed | | | | and refined the logic | | | | of Aristotle and | | | | Chrysippus as | | | | communicated by | | | | Boethius. | | | | | | | | -Abelard originated | | | | the theory of | | | | universals that | | | | traced the universal | | | | character of general | | | | terms to concepts in | | | | the mind, rather than | | | | to natures existing | | | | outside the mind as | | | | Aristotle held. In | | | | addition, Abelard | | | | distinguished | | | | arguments that are | | | | valid because of | | | | their form from those | | | | that are valid | | | | because of their | | | | content. | | | | | | | | -After Abelard, the | | | | study of logic during | | | | the Middle Ages | | | | flourished through | | | | the work of numerous | | | | philosophers. The | | | | most original | | | | contributions from | | | | this period were made | | | | by William of Ockham | | | | (ca. 1285-1347). | | | | Ockham extended the | | | | theory of modal | | | | logic, conducted an | | | | exhaustive study of | | | | the forms of valid | | | | and invalid | | | | syllogisms, and | | | | further developed the | | | | idea of metalanguage, | | | | a higher-level | | | | language used to | | | | discuss linguistic | | | | entities such as | | | | words, terms and | | | | propositions. | | | | | | | | -Toward the middle of | | | | the fifteenth | | | | century, a reaction | | | | set in against the | | | | logic of the Middle | | | | Ages. Rhetoric | | | | largely displaced | | | | logic as the primary | | | | focus of attention. A | | | | reawakening did not | | | | occur until two | | | | hundred years later | | | | through the work of | | | | Gottfried Wilhelm | | | | Leibniz (1646-1716). | | | | | | | | -Leibniz attempted to | | | | develop a symbolic | | | | language or calculus | | | | that could be used to | | | | settle all forms of | | | | disputes. As a result | | | | of this work, Leibniz | | | | is sometimes credited | | | | with being the father | | | | of symbolic logic. | | | | Leibniz's efforts to | | | | symbolize logic were | | | | carried into the | | | | nineteenth century by | | | | Bernard Bolzano | | | | (1781-1848). | | | | | | | | -In the middle of the | | | | nineteenth century, | | | | logic commenced an | | | | extremely rapid | | | | period of development | | | | that has continued to | | | | this day. Work in | | | | symbolic logic was | | | | done by many | | | | philosophers and | | | | mathematicians, | | | | including Augustus De | | | | Morgan (1806-1871), | | | | George Boole | | | | (1815-1864), William | | | | Stanley Jevons | | | | (1835-1882), and John | | | | Venn (1834-1923). A | | | | revival in inductive | | | | logic was initiated | | | | by the British | | | | philosopher John | | | | Stuart Mill | | | | (1806-1873). | | | | | | | | -Across the Atlantic, | | | | the American | | | | philosopher Charles | | | | Sanders Peirce | | | | (1839-1914) developed | | | | a logic of relations, | | | | invented symbolic | | | | quantifiers, and | | | | suggested the | | | | truth-table method | | | | for formulas in | | | | propositional logic. | | | | The truth-table | | | | method was completed | | | | independently by Emil | | | | Post (1897-1954) and | | | | Ludwig Wittgenstein | | | | (1889-1951). | | | | | | | | -Toward the end of | | | | the nineteenth | | | | century, the | | | | foundations of modern | | | | mathematical logic | | | | were laid by Gottlob | | | | Frege (1848-1925). | | | | Frege's work was | | | | continued into the | | | | twentieth century by | | | | Alfred North | | | | Whitehead (1861-1947) | | | | and Bertrand Russell | | | | (1872-1970). | | | | | | | | -During the twentieth | | | | century, much of the | | | | work in logic focused | | | | on the formalization | | | | of logical systems | | | | and on questions | | | | dealing with the | | | | completeness and | | | | consistency of such | | | | systems. A now-famous | | | | theorem proved by | | | | Kurt Godel | | | | (1906-1978) states | | | | that in any formal | | | | system adequate for | | | | number theory there | | | | exists an undecidable | | | | formula, a formula | | | | such that neither it | | | | nor its negation is | | | | derivable from the | | | | axioms of the system. | +-----------------------+-----------------------+-----------------------+ | | Basic Processes in | -Simple Apprehension: | | | Logic | It is a mental | | | | operation whereby the | | | | mind understands the | | | | essence or general | | | | meaning of a thing | | | | without affirming or | | | | denying anything | | | | about it. | | | | | | | | -Judgment: It is a | | | | mental operation | | | | through which the | | | | mind pronounces, | | | | enunciates, or | | | | declares the | | | | agreement or | | | | disagreement of two | | | | ideas. | | | | | | | | -Reasoning: It is a | | | | mental operation | | | | through which the | | | | agreement or | | | | disagreement of two | | | | ideas is inferred | | | | from their known | | | | relation to a third | | | | idea. | +-----------------------+-----------------------+-----------------------+ | | References | Art of Critical | | | | Thinking, The: Logic | | | | for Filipino Students | | | | / Lionel E. | | | | Buenaflor. 3^rd^ ed. | | | | Mandaluyong City: | | | | Books Atbp. | | | | Publishing, 2014. | | | | | | | | Concise Introduction | | | | to Logic, A / Patrick | | | | J. Hurley, Lori | | | | Watson. 13^th^ ed. | | | | Boston, MA: Cengage | | | | Learning, 2018. | | | | | | | | Introduction to Logic | | | | / Andrew H. | | | | Bachhuber. New York: | | | | Appleton-Century-Crof | | | | ts, | | | | 1957. | | | | | | | | Introduction to Logic | | | | / Irving M. Copi, | | | | Carl Cohen, Kenneth | | | | McMahon. 14^th^ ed. | | | | Harlow: Pearson, | | | | 2014. | | | | | | | | Introduction to Logic | | | | / Michael Genesereth | | | | and Eric Kao. 2^nd^ | | | | ed. San Rafael, CA: | | | | Morgan and Claypool | | | | Publishers, 2013. | | | | | | | | Introduction to Logic | | | | and Critical Thinking | | | | / Merrilee H. Salmon. | | | | 6^th^ ed. Boston, MA: | | | | Wadsworth Cengage | | | | Learning, 2013. | | | | | | | | Logic: Basic | | | | Principles of | | | | Critical Thinking / | | | | Willie A. Buñag, | | | | Joselito B. 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Boston, MA: | | | | McGraw Hill Higher | | | | Education, 2009. | | | | | | | | Logic for Filipinos / | | | | Priscilliano T. | | | | Bauzon. 3^rd^ ed. | | | | Mandaluyong City: | | | | National Book Store, | | | | 2013. | | | | | | | | Power of Logic, The / | | | | Frances | | | | Howard-Snyder, Daniel | | | | Howard Snyder, Ryan | | | | Wasserman. 4^th^ ed. | | | | Boston, MA: McGraw | | | | Hill Higher | | | | Education, 2009. | | | | | | | | Think: Critical | | | | Thinking and Logic | | | | Skills for Everyday | | | | Life / Judith A. | | | | Ross. 4^th^ ed. New | | | | York: McGraw Hill | | | | Education, 2017. | +-----------------------+-----------------------+-----------------------+