Truth-Functional Logic A. The

Total Page:16

File Type:pdf, Size:1020Kb

Truth-Functional Logic A. The CHAPTER 4: TRUTH-FUNCTIONAL LOGIC A. THE PROPOSITIONAL CALCULUS Consider the following two-premise deductive arguments: Argument Argument Form (a) Today is Wednesday or today is Thursday. A or B Today is not Thursday not-B Therefore, today is Wednesday. A (b) If the gas tank is empty, then the car will not start. If C then not-D The gas tank is empty. C Therefore, the car will not start. not-D Now, these two examples embody two common argument forms. It will be the purpose of this chapter to develop a system of logic by means of which we can evaluate such arguments. This system of logic is called Truth-Functional or modern Logic. In truth-functional logic we begin with atomic or simple propositions as our building blocks, from which we construct more complex propositions and arguments. The propositional calculus provides us with techniques for calculating the truth or falsity of a complex proposition based on the truth or falsity of the simple propositions from which it is constructed. These techniques also provide us with a means of calculating whether an argument is valid or invalid. 185 I. Atomic (simple) Propositions In the propositional calculus atomic or simple propositions are used to build compound propositions of increasingly high levels of complexity. The truth value of a compound can then be calculated from the truth values of its simple propositions. The predicate calculus provides us with a way of reconstructing the categorical propositions of traditional Aristotelian logic so that they can also be represented in modern truth-functional terms. Individuals and Properties: I. Constants In truth-functional logic, we specify a universe of discourse by specifying the individuals that exist in that universe, and the properties those individuals may have. The names of individuals in our universe of discourse are abbreviated using lower case alphabets a, b, c, .. .w. The names for the properties possessed by these individuals are abbreviated using upper case alphabets A,B, C, … Z. For example, let j designate the individual John, and W designate the property of being wet. Then Wx = x is wet and Wj = John is wet. And if we let d designate Debbie and A designate the property of being asleep, then Ax = x is asleep and Ad = Debbie is asleep. If the names “John” and “Debbie” refer to actual individuals, then the propositions symbolized as Wj, Wd, Ad, and Aj are each actually either true or false. The individuals designated by j and d remain constant, no matter what property either is alleged to have. Likewise, the properties designated by W and A remain constant, no matter what individual is alleged to possess those 186 properties. Once a name has been assigned to a particular individual or property within a given discourse, it does not change. II. Variables The propositional form Wx attributes the property of being wet to an individual, x, where x could refer to any of the individuals in our universe of discourse. x is an individual variable, and Wx is a propositional form that becomes an actual proposition when x is replaced by the (abbreviated) name of an actual individual. Individual variables are place-holders for the names of individuals. The lower case alphabets x, y, and z are typically used as individual variables. A propositional form is neither true nor false, but it becomes true or false when its individual variables are replaced by individual constants. In a similar fashion, every proposition that attributes a property to a particular individual, j, has the propositional form Φj (read “phi of j” or “j has the property Φ; Φ is the Greek alphabet pronounced “phi”). Greek alphabets are used as place holders for properties that individuals may have, and are called predicate variables. Thus, Φj is a propositional form that becomes an actual proposition when Φ is replaced by the name of an actual property (e.g. W or A), which is then either truly or falsely attributed to John. In the examples used so far, some individual, x, is alleged to have some property, Φ. When a property can be attributed to a single individual, it is called a monadic or one-place predicate. Thus, Wd can be true independently of whether any other individual in our universe of discourse is wet. The following examples of one-place predicates are designated by sub- scripted alphabets. In this way, an infinite number of predicates can be generated and combined with the names of individuals to produce statements that are either true or false. 187 A1x = x is a Republican B1x = x is a human A2x = x is a Democrat B2x = x is a college professor A3x = x is an American. B3x = x is a woman A4x = x is the USA president B4x = x is a man A5x = x is a Christian B5x = x is a musician A6x = x is hardworking. B6x = x is a Muslim A7x = x is asleep B7x = x is a Buddhist A8x = x is a Hindu B8x = x is wealthy A9x = x is an engineer B9x = x is a soccer player A10x = x is Jewish B10x = x is a basketball player 4.I.1. Exercise: Using lower case letters to designate the names of actual individuals, construct one true and one false proposition for each of the above predicates. III. Relational Properties But not all properties can meaningfully be attributed to just a single individual. Many properties point to a relationship between two or more individuals rather than to an attribute of a single individual. For example, if M designates the property of being married, then Md (Debbie is married) is either true or false. But being married does not refer to the property of a single individual, but designates a relationship between (at least two) individuals. Thus, construing the property of being married as if it were like the property of being wet is misleading. 188 While Wd can be true independently of whether any other individual is wet, Md cannot be true independently of whether any other individual is married. A statement of the form Mx is really short for Mxy, which reads x is married to y. Thus, if Md is true, then there must be some other individual, e, such that Mde. Being married is not a one-place predicate, but (in a monogamous universe) a two place predicate. A two place predicate designates a relationship between two individuals, rather than a property of one individual. Following are some examples of statement forms with two-place predicates: Nxy = x is next to y Wxy = x weighs more than y Txy = x is playing tennis with y Exy = x is an employee of y Mxy = x is the mother of y Fxy = x is the father of y Note that while it is true that (if Nxy then Nyx), it is false that (if Wxy then Wyx). Some two- place predicates are commutative, but many are not. Following are some examples of two-place predicates that are often expressed as if they were one-place predicates: One Place What is meant Two Place x is in love Lx x is in love with y. Lxy x is angry Ax x is angry at y Axy x is a parent. Px x is a parent of y. Pxy x is strong. Sx x is stronger than y. Sxy x is a veteran Vx x is a veteran of war y Vxy x is reading Rxy x is reading y Rxy x is eating Ex x is eating y Exy Some properties refer to relationships between three individuals. Thus, ‘x is between y and z’ = Bxyz. Likewise, ‘x is a child’ is shorthand for ‘x is a child of y and z’ or Cxyz. 189 ‘Between’ and ‘is a child’ are three-place predicates. Some predicates actually refer to a relationship between four individuals, yet appear to be about one individual. Thus, ‘x is playing tennis doubles’ (or TDx) may seem to be saying something only about x. But it is shorthand for ‘x is playing tennis doubles with y, z and w’ ( or TDxyzw). We symbolize 1-place, 2-place, 3- place, and n-place predicates as Ax, Bxy, Cxyz, Dwxyz, … These statement forms become actual statements that are true or false when each variable is replaced by a constant. 4.I.2. Exercises: Cxyz = “x is between y and z.” Let a, b, and c be distinct points on a straight line. Answer the following: 1.) C is a ____-place predicate. 2.) If Cabc is true, then Cbca must be ____(True/False) 3.) If Cabc is true, then Cacb must be _____(True/False) 4.I.3. Exercises: Mxy = “x is married to y.” Pxyz = “x and y are the parents of z.” Bonnie = b, Joe = j, and Ted = t. Answer the following: 1.) M is a ___-place predicate. 2.) P is a ____-place predicate. Symbolize each of the following statements: 3.) Bonnie is married to Joe. _______ 4.) Ted and Joe are the parents of Bonnie. _______ 5.) Ted is married to Joe. 6.) Ted is married to Bonnie. _______ 7.) Joe and Bonnie are the parents of Ted. _______ 190 II. Compound Propositions A compound proposition is one that contains other propositions as component parts. For example, the proposition, “Today is Wednesday or today is Thursday” contains two component propositions: “Today is Wednesday” and "Today is Thursday.” Similarly, the proposition, “If the gas tank is empty, then the car will not start” is a compound proposition that contains the two component propositions: “The gas tank is empty,” and “The car will not start.” Propositions that do not contain other propositions are called simple propositions.
Recommended publications
  • Chapter 2 Introduction to Classical Propositional
    CHAPTER 2 INTRODUCTION TO CLASSICAL PROPOSITIONAL LOGIC 1 Motivation and History The origins of the classical propositional logic, classical propositional calculus, as it was, and still often is called, go back to antiquity and are due to Stoic school of philosophy (3rd century B.C.), whose most eminent representative was Chryssipus. But the real development of this calculus began only in the mid-19th century and was initiated by the research done by the English math- ematician G. Boole, who is sometimes regarded as the founder of mathematical logic. The classical propositional calculus was ¯rst formulated as a formal ax- iomatic system by the eminent German logician G. Frege in 1879. The assumption underlying the formalization of classical propositional calculus are the following. Logical sentences We deal only with sentences that can always be evaluated as true or false. Such sentences are called logical sentences or proposi- tions. Hence the name propositional logic. A statement: 2 + 2 = 4 is a proposition as we assume that it is a well known and agreed upon truth. A statement: 2 + 2 = 5 is also a proposition (false. A statement:] I am pretty is modeled, if needed as a logical sentence (proposi- tion). We assume that it is false, or true. A statement: 2 + n = 5 is not a proposition; it might be true for some n, for example n=3, false for other n, for example n= 2, and moreover, we don't know what n is. Sentences of this kind are called propositional functions. We model propositional functions within propositional logic by treating propositional functions as propositions.
    [Show full text]
  • Aristotle's Illicit Quantifier Shift: Is He Guilty Or Innocent
    Aristos Volume 1 Issue 2 Article 2 9-2015 Aristotle's Illicit Quantifier Shift: Is He Guilty or Innocent Jack Green The University of Notre Dame Australia Follow this and additional works at: https://researchonline.nd.edu.au/aristos Part of the Philosophy Commons, and the Religious Thought, Theology and Philosophy of Religion Commons Recommended Citation Green, J. (2015). "Aristotle's Illicit Quantifier Shift: Is He Guilty or Innocent," Aristos 1(2),, 1-18. https://doi.org/10.32613/aristos/ 2015.1.2.2 Retrieved from https://researchonline.nd.edu.au/aristos/vol1/iss2/2 This Article is brought to you by ResearchOnline@ND. It has been accepted for inclusion in Aristos by an authorized administrator of ResearchOnline@ND. For more information, please contact [email protected]. Green: Aristotle's Illicit Quantifier Shift: Is He Guilty or Innocent ARISTOTLE’S ILLICIT QUANTIFIER SHIFT: IS HE GUILTY OR INNOCENT? Jack Green 1. Introduction Aristotle’s Nicomachean Ethics (from hereon NE) falters at its very beginning. That is the claim of logicians and philosophers who believe that in the first book of the NE Aristotle mistakenly moves from ‘every action and pursuit aims at some good’ to ‘there is some one good at which all actions and pursuits aim.’1 Yet not everyone is convinced of Aristotle’s seeming blunder.2 In lieu of that, this paper has two purposes. Firstly, it is an attempt to bring some clarity to that debate in the face of divergent opinions of the location of the fallacy; some proposing it lies at I.i.1094a1-3, others at I.ii.1094a18-22, making it difficult to wade through the literature.
    [Show full text]
  • Propositional Logic - Basics
    Outline Propositional Logic - Basics K. Subramani1 1Lane Department of Computer Science and Electrical Engineering West Virginia University 14 January and 16 January, 2013 Subramani Propositonal Logic Outline Outline 1 Statements, Symbolic Representations and Semantics Boolean Connectives and Semantics Subramani Propositonal Logic (i) The Law! (ii) Mathematics. (iii) Computer Science. Definition Statement (or Atomic Proposition) - A sentence that is either true or false. Example (i) The board is black. (ii) Are you John? (iii) The moon is made of green cheese. (iv) This statement is false. (Paradox). Statements, Symbolic Representations and Semantics Boolean Connectives and Semantics Motivation Why Logic? Subramani Propositonal Logic (ii) Mathematics. (iii) Computer Science. Definition Statement (or Atomic Proposition) - A sentence that is either true or false. Example (i) The board is black. (ii) Are you John? (iii) The moon is made of green cheese. (iv) This statement is false. (Paradox). Statements, Symbolic Representations and Semantics Boolean Connectives and Semantics Motivation Why Logic? (i) The Law! Subramani Propositonal Logic (iii) Computer Science. Definition Statement (or Atomic Proposition) - A sentence that is either true or false. Example (i) The board is black. (ii) Are you John? (iii) The moon is made of green cheese. (iv) This statement is false. (Paradox). Statements, Symbolic Representations and Semantics Boolean Connectives and Semantics Motivation Why Logic? (i) The Law! (ii) Mathematics. Subramani Propositonal Logic (iii) Computer Science. Definition Statement (or Atomic Proposition) - A sentence that is either true or false. Example (i) The board is black. (ii) Are you John? (iii) The moon is made of green cheese. (iv) This statement is false.
    [Show full text]
  • Scope Ambiguity in Syntax and Semantics
    Scope Ambiguity in Syntax and Semantics Ling324 Reading: Meaning and Grammar, pg. 142-157 Is Scope Ambiguity Semantically Real? (1) Everyone loves someone. a. Wide scope reading of universal quantifier: ∀x[person(x) →∃y[person(y) ∧ love(x,y)]] b. Wide scope reading of existential quantifier: ∃y[person(y) ∧∀x[person(x) → love(x,y)]] 1 Could one semantic representation handle both the readings? • ∃y∀x reading entails ∀x∃y reading. ∀x∃y describes a more general situation where everyone has someone who s/he loves, and ∃y∀x describes a more specific situation where everyone loves the same person. • Then, couldn’t we say that Everyone loves someone is associated with the semantic representation that describes the more general reading, and the more specific reading obtains under an appropriate context? That is, couldn’t we say that Everyone loves someone is not semantically ambiguous, and its only semantic representation is the following? ∀x[person(x) →∃y[person(y) ∧ love(x,y)]] • After all, this semantic representation reflects the syntax: In syntax, everyone c-commands someone. In semantics, everyone scopes over someone. 2 Arguments for Real Scope Ambiguity • The semantic representation with the scope of quantifiers reflecting the order in which quantifiers occur in a sentence does not always represent the most general reading. (2) a. There was a name tag near every plate. b. A guard is standing in front of every gate. c. A student guide took every visitor to two museums. • Could we stipulate that when interpreting a sentence, no matter which order the quantifiers occur, always assign wide scope to every and narrow scope to some, two, etc.? 3 Arguments for Real Scope Ambiguity (cont.) • But in a negative sentence, ¬∀x∃y reading entails ¬∃y∀x reading.
    [Show full text]
  • The Critical Thinking Toolkit
    Galen A. Foresman, Peter S. Fosl, and Jamie Carlin Watson The CRITICAL THINKING The THE CRITICAL THINKING TOOLKIT GALEN A. FORESMAN, PETER S. FOSL, AND JAMIE C. WATSON THE CRITICAL THINKING TOOLKIT This edition first published 2017 © 2017 John Wiley & Sons, Inc. Registered Office John Wiley & Sons Ltd, The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, UK Editorial Offices 350 Main Street, Malden, MA 02148-5020, USA 9600 Garsington Road, Oxford, OX4 2DQ, UK The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, UK For details of our global editorial offices, for customer services, and for information about how to apply for permission to reuse the copyright material in this book please see our website at www.wiley.com/wiley-blackwell. The right of Galen A. Foresman, Peter S. Fosl, and Jamie C. Watson to be identified as the authors of this work has been asserted in accordance with the UK Copyright, Designs and Patents Act 1988. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, except as permitted by the UK Copyright, Designs and Patents Act 1988, without the prior permission of the publisher. Wiley also publishes its books in a variety of electronic formats. Some content that appears in print may not be available in electronic books. Designations used by companies to distinguish their products are often claimed as trademarks. All brand names and product names used in this book are trade names, service marks, trademarks or registered trademarks of their respective owners.
    [Show full text]
  • Deduction (I) Tautologies, Contradictions And
    D (I) T, & L L October , Tautologies, contradictions and contingencies Consider the truth table of the following formula: p (p ∨ p) () If you look at the final column, you will notice that the truth value of the whole formula depends on the way a truth value is assigned to p: the whole formula is true if p is true and false if p is false. Contrast the truth table of (p ∨ p) in () with the truth table of (p ∨ ¬p) below: p ¬p (p ∨ ¬p) () If you look at the final column, you will notice that the truth value of the whole formula does not depend on the way a truth value is assigned to p. The formula is always true because of the meaning of the connectives. Finally, consider the truth table table of (p ∧ ¬p): p ¬p (p ∧ ¬p) () This time the formula is always false no matter what truth value p has. Tautology A statement is called a tautology if the final column in its truth table contains only ’s. Contradiction A statement is called a contradiction if the final column in its truth table contains only ’s. Contingency A statement is called a contingency or contingent if the final column in its truth table contains both ’s and ’s. Let’s consider some examples from the book. Can you figure out which of the following sentences are tautologies, which are contradictions and which contingencies? Hint: the answer is the same for all the formulas with a single row. () a. (p ∨ ¬p), (p → p), (p → (q → p)), ¬(p ∧ ¬p) b.
    [Show full text]
  • Sets, Propositional Logic, Predicates, and Quantifiers
    COMP 182 Algorithmic Thinking Sets, Propositional Logic, Luay Nakhleh Computer Science Predicates, and Quantifiers Rice University !1 Reading Material ❖ Chapter 1, Sections 1, 4, 5 ❖ Chapter 2, Sections 1, 2 !2 ❖ Mathematics is about statements that are either true or false. ❖ Such statements are called propositions. ❖ We use logic to describe them, and proof techniques to prove whether they are true or false. !3 Propositions ❖ 5>7 ❖ The square root of 2 is irrational. ❖ A graph is bipartite if and only if it doesn’t have a cycle of odd length. ❖ For n>1, the sum of the numbers 1,2,3,…,n is n2. !4 Propositions? ❖ E=mc2 ❖ The sun rises from the East every day. ❖ All species on Earth evolved from a common ancestor. ❖ God does not exist. ❖ Everyone eventually dies. !5 ❖ And some of you might already be wondering: “If I wanted to study mathematics, I would have majored in Math. I came here to study computer science.” !6 ❖ Computer Science is mathematics, but we almost exclusively focus on aspects of mathematics that relate to computation (that can be implemented in software and/or hardware). !7 ❖Logic is the language of computer science and, mathematics is the computer scientist’s most essential toolbox. !8 Examples of “CS-relevant” Math ❖ Algorithm A correctly solves problem P. ❖ Algorithm A has a worst-case running time of O(n3). ❖ Problem P has no solution. ❖ Using comparison between two elements as the basic operation, we cannot sort a list of n elements in less than O(n log n) time. ❖ Problem A is NP-Complete.
    [Show full text]
  • Emergent Properties of Terrorist Networks, Percolation and Social Narrative
    Emergent Properties of Terrorist Networks, Percolation and Social Narrative Maurice Passman Adaptive Risk Technology, Ltd. London, UK [email protected] Philip V. Fellman American Military University Charles Town, WV [email protected] Abstract In this paper, we have initiated an attempt to develop and understand the driving mechanisms that underlies fourth-generation warfare (4GW). We have undertaken this from a perspective of endeavoring to understand the drivers of these events (i.e. the 'Physics') from a Complexity perspective by using a threshold-type percolation model. We propose to integrate this strategic level model with tactical level Big Data, behavioral, statistical projections via a ‘fractal’ operational level model and to construct a hierarchical framework that allows dynamic prediction. Our initial study concentrates on this strategic level, i.e. a percolation model. Our main conclusion from this initial study is that extremist terrorist events are not solely driven by the size of a supporting population within a socio-geographical location but rather a combination of ideological factors that also depends upon the involvement of the host population. This involvement, through the social, political and psychological fabric of society, not only contributes to the active participation of terrorists within society but also directly contributes to and increases the likelihood of the occurrence of terrorist events. Our calculations demonstrate the links between Islamic extremist terrorist events, the ideologies within the Muslim and non-Muslim population that facilitates these terrorist events (such as Anti-Zionism) and anti- Semitic occurrences of violence against the Jewish population. In a future paper, we hope to extend the work undertaken to construct a predictive model and extend our calculations to other forms of terrorism such as Right Wing fundamentalist terrorist events within the USA.
    [Show full text]
  • Argument Forms and Fallacies
    6.6 Common Argument Forms and Fallacies 1. Common Valid Argument Forms: In the previous section (6.4), we learned how to determine whether or not an argument is valid using truth tables. There are certain forms of valid and invalid argument that are extremely common. If we memorize some of these common argument forms, it will save us time because we will be able to immediately recognize whether or not certain arguments are valid or invalid without having to draw out a truth table. Let’s begin: 1. Disjunctive Syllogism: The following argument is valid: “The coin is either in my right hand or my left hand. It’s not in my right hand. So, it must be in my left hand.” Let “R”=”The coin is in my right hand” and let “L”=”The coin is in my left hand”. The argument in symbolic form is this: R ˅ L ~R __________________________________________________ L Any argument with the form just stated is valid. This form of argument is called a disjunctive syllogism. Basically, the argument gives you two options and says that, since one option is FALSE, the other option must be TRUE. 2. Pure Hypothetical Syllogism: The following argument is valid: “If you hit the ball in on this turn, you’ll get a hole in one; and if you get a hole in one you’ll win the game. So, if you hit the ball in on this turn, you’ll win the game.” Let “B”=”You hit the ball in on this turn”, “H”=”You get a hole in one”, and “W”=”you win the game”.
    [Show full text]
  • Logical Reasoning
    updated: 11/29/11 Logical Reasoning Bradley H. Dowden Philosophy Department California State University Sacramento Sacramento, CA 95819 USA ii Preface Copyright © 2011 by Bradley H. Dowden This book Logical Reasoning by Bradley H. Dowden is licensed under a Creative Commons Attribution- NonCommercial-NoDerivs 3.0 Unported License. That is, you are free to share, copy, distribute, store, and transmit all or any part of the work under the following conditions: (1) Attribution You must attribute the work in the manner specified by the author, namely by citing his name, the book title, and the relevant page numbers (but not in any way that suggests that the book Logical Reasoning or its author endorse you or your use of the work). (2) Noncommercial You may not use this work for commercial purposes (for example, by inserting passages into a book that is sold to students). (3) No Derivative Works You may not alter, transform, or build upon this work. An earlier version of the book was published by Wadsworth Publishing Company, Belmont, California USA in 1993 with ISBN number 0-534-17688-7. When Wadsworth decided no longer to print the book, they returned their publishing rights to the original author, Bradley Dowden. If you would like to suggest changes to the text, the author would appreciate your writing to him at [email protected]. iii Praise Comments on the 1993 edition, published by Wadsworth Publishing Company: "There is a great deal of coherence. The chapters build on one another. The organization is sound and the author does a superior job of presenting the structure of arguments.
    [Show full text]
  • 12 Propositional Logic
    CHAPTER 12 ✦ ✦ ✦ ✦ Propositional Logic In this chapter, we introduce propositional logic, an algebra whose original purpose, dating back to Aristotle, was to model reasoning. In more recent times, this algebra, like many algebras, has proved useful as a design tool. For example, Chapter 13 shows how propositional logic can be used in computer circuit design. A third use of logic is as a data model for programming languages and systems, such as the language Prolog. Many systems for reasoning by computer, including theorem provers, program verifiers, and applications in the field of artificial intelligence, have been implemented in logic-based programming languages. These languages generally use “predicate logic,” a more powerful form of logic that extends the capabilities of propositional logic. We shall meet predicate logic in Chapter 14. ✦ ✦ ✦ ✦ 12.1 What This Chapter Is About Section 12.2 gives an intuitive explanation of what propositional logic is, and why it is useful. The next section, 12,3, introduces an algebra for logical expressions with Boolean-valued operands and with logical operators such as AND, OR, and NOT that Boolean algebra operate on Boolean (true/false) values. This algebra is often called Boolean algebra after George Boole, the logician who first framed logic as an algebra. We then learn the following ideas. ✦ Truth tables are a useful way to represent the meaning of an expression in logic (Section 12.4). ✦ We can convert a truth table to a logical expression for the same logical function (Section 12.5). ✦ The Karnaugh map is a useful tabular technique for simplifying logical expres- sions (Section 12.6).
    [Show full text]
  • Reasoning in School
    Reasoning in School For this I’m indebted to my Dad, who has over the years wisely entertained my impassioned ideas about education, to my Mom, whose empathy I’ve internalized, and to many liberal teachers. Preface A fifth grader taught me the word ‘metacognition’, which, following her, we can take to mean “thinking about thinking”. This is an analogical exercise in metacognition. It is secondarily an introduction to the process of reasoning and primarily an examination of basic notions about that process, especially those that are supposed commonsense and those that are missing from our self-concepts. As it turns out, subjecting popular metacognitive attitudes to even minor scrutiny calls some of them seriously into question. It is my goal to do so, and to form in the mind of the reader better founded beliefs about reasoning and thereby a more accurate, and consequently empowering, self-understanding. I would love to set in motion the mind that frees itself. I am in the end interested in reasoning in school as it relates to the practice of Philosophy for Children (p4c). It is amazing that reasoning is not a part of the K-12 curriculum. That it is not I find plainly unjustifiable and seriously unjust. In what follows I defend this position and consider p4c in light of it. Because I am focused on beliefs about thinking, as opposed to the cognitive psychology of thought, I am afforded some writing leeway. I am not a psychologist, but I have a fair metacognitive confidence thanks to my background in philosophy.
    [Show full text]