Theories of Truth Powerpoint


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Theories of Truth Powerpoint

  1. 1. Three Great Theories of Truth Unit 6
  2. 2. Correspondence Theory <ul><li>The dominant theory, especially popular with empiricists </li></ul><ul><li>Correspondence Theory proposes that a proposition is true if it corresponds to the facts </li></ul><ul><ul><ul><li>Example: “The apple is sitting on the table” can be true only if the apple is in fact sitting on the table. </li></ul></ul></ul><ul><li>Often traced back to Thomas Aquinas’ version: “A judgment is said to be true when it conforms to the external reality” ( Summa Theologiae, Q. 16) </li></ul><ul><ul><ul><li>Also leaves room for the idea that “true” may be applied to people (a “true friend”) as well as to thoughts </li></ul></ul></ul><ul><li>Two main versions of Correspondence Theory: object-based, and fact-based (currently prominent) </li></ul>
  3. 3. Correspondence Theory <ul><li>Strengths: </li></ul><ul><ul><ul><li>Simplicity </li></ul></ul></ul><ul><ul><ul><li>Appeal to common sense </li></ul></ul></ul><ul><li>Weaknesses </li></ul><ul><ul><ul><li>Difficulties pertaining to linguistics </li></ul></ul></ul><ul><ul><ul><li>Falls prey to circular reasoning </li></ul></ul></ul><ul><ul><ul><li>Awkwardness in application to mathematics </li></ul></ul></ul><ul><ul><ul><li>Leads to skepticism about the external world </li></ul></ul></ul>
  4. 4. Correspondence Theory - Strengths <ul><li>Simplicity </li></ul><ul><li>Appeal to Common Sense </li></ul><ul><ul><ul><li>In order to prove that “It is raining today” is true, according to the correspondence theory, all one must do is look out the window and verify that it is in fact raining </li></ul></ul></ul><ul><ul><ul><li>According to Descartes, “I have never had any doubts about truth, because it seems a notion so transcendentally clear that nobody can be ignorant of it…the word ‘truth,’ in the strict sense, denotes the conformity of thought with its object” (‘ Letter to Mersenne: 16 October 1639,’ The Philosophical Writings of Descartes, vol. 3 ) </li></ul></ul></ul>
  5. 5. Correspondence Theory - Weaknesses <ul><li>Linguistic Issues </li></ul><ul><ul><ul><li>How can a word or sentence correspond to things that are nothing like language? </li></ul></ul></ul><ul><ul><ul><li>Some philosophers claim that asserting that a word corresponds to an actual object in reality is rather like comparing apples and oranges </li></ul></ul></ul><ul><ul><ul><li>Language is by nature ambiguous – a word for an object differs from culture to culture, and even from person to person </li></ul></ul></ul><ul><ul><ul><ul><ul><li>For example, wet, non-frozen precipitation that falls from the sky is called “rain” in English, “la pluie” in French, and “regen” in German. </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>In addition, even within a language, one person may call a light rain a “drizzle” while another might call it a “shower” </li></ul></ul></ul></ul></ul><ul><ul><ul><li>This ambiguity can cause issues when illustrating how a word corresponds to a particular object or event </li></ul></ul></ul>
  6. 6. Correspondence Theory - Weaknesses <ul><li>Circular Reasoning </li></ul><ul><ul><ul><li>Correspondence Theory claims that a proposition is true if it corresponds to the facts </li></ul></ul></ul><ul><ul><ul><li>What is a fact? </li></ul></ul></ul><ul><ul><ul><ul><ul><li>A fact is, by definition, a true proposition </li></ul></ul></ul></ul></ul><ul><ul><ul><li>So a proposition is true if it corresponds another proposition that is true </li></ul></ul></ul><ul><ul><ul><ul><ul><li>The facts must also be proven to be true – by showing that they correspond to other facts </li></ul></ul></ul></ul></ul><ul><ul><ul><li>An important rule of writing a definition is that one cannot use the word you are defining in the definition of the word, which is what Correspondence Theory does, in a sense </li></ul></ul></ul><ul><ul><ul><ul><ul><li>It’s rather like defining apple as an apple-like object </li></ul></ul></ul></ul></ul>
  7. 7. Correspondence Theory - Weaknesses <ul><li>Mathematical Applications </li></ul><ul><ul><ul><li>Correspondence Theory may appear to make sense when it applied to language, but it runs into difficulty when applied to the truths of mathematics </li></ul></ul></ul><ul><ul><ul><li>What “factual reality” does the proposition 5+2=7 correspond to? </li></ul></ul></ul><ul><ul><ul><ul><ul><li>We might point to practical examples, such as 5 pencils plus 2 pencils leaves you with 7 pencils </li></ul></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>While that is true, the original proposition says nothing about pencils – and we certainly recognize that there is no such object as ‘5’ or ‘2’ in the real world. </li></ul></ul></ul></ul></ul><ul><ul><ul><li>The world of numbers appears to be too theoretical to be accurately explained by the Correspondence Theory </li></ul></ul></ul>
  8. 8. Coherence Theory <ul><li>Preferred by many idealists </li></ul><ul><ul><ul><li>For idealists, reality is like a collection of beliefs, which makes the coherence theory particularly attractive </li></ul></ul></ul><ul><li>The coherence theory of truth states that if a proposition coheres with all the other propositions taken to be true, then it is true. </li></ul><ul><ul><ul><li>The truth of a belief can only consist in its coherence with other beliefs; truth comes in degrees </li></ul></ul></ul><ul><li>Coherence theorists hold that truth consists in coherence with a set of beliefs or with a set of propositions held to be true, not just an arbitrary collection of propositions </li></ul>
  9. 9. Coherence Theory <ul><li>Strengths: </li></ul><ul><ul><ul><li>Makes sense out of the idea of mathematical truths </li></ul></ul></ul><ul><ul><ul><ul><li>Ex: (5+2=7) is true because: 7=7 ; 1+6=7 ; 21/3=(2x3)+1; are all true </li></ul></ul></ul></ul><ul><li>Weaknesses </li></ul><ul><ul><ul><li>Like the Correspondence theory, the Coherence theory falls prey to circular reasoning </li></ul></ul></ul><ul><ul><ul><ul><li>Ex: Proposition A is true because propositions B and C are true. But how do you know B is true? Because proposition A and C are true. But what external evidence is there to support the truth of any of these propositions? </li></ul></ul></ul></ul>
  10. 10. Pragmatism <ul><li>William James is considered the father of pragmatism </li></ul><ul><li>However, in order to understand James’ presentation of pragmatism we must draw a distinction between meaning and truth. </li></ul><ul><ul><li>A sentence is meaningful only if believing it would make a practical difference in your life as opposed to believing some alternative to it. </li></ul></ul><ul><ul><ul><li>Example: Proposition A: There is a gaping hole in the middle of the cafeteria. </li></ul></ul></ul><ul><ul><ul><ul><li>Would believing this proposition to be true make a practical difference in your life? </li></ul></ul></ul></ul><ul><ul><ul><ul><ul><li>It is safe to assume that one would take a path that avoids the middle of the cafeteria if one believed that there was a gaping hole there. </li></ul></ul></ul></ul></ul>
  11. 11. Pragmatism, cont’d… <ul><li>The previous example is an illustration of a meaningful proposition – belief in it (or lack thereof) makes a practical difference in one’s life. </li></ul><ul><li>What about truth? </li></ul><ul><ul><ul><li>Only meaningful sentences can be true or false </li></ul></ul></ul><ul><ul><ul><li>James’ take on both the coherence and correspondence theories of truth is that they are not competing theories, but rather different tools to be applied to beliefs to see if those beliefs work </li></ul></ul></ul>
  12. 12. Pragmatism, cont’d <ul><li>“ Ideas (which themselves are but parts of our experience) become true just insofar as they help us to get into satisfactory relations with other parts of our experience,…truth in our ideas means their power to ‘work’” – William James, Pragmatism (49) </li></ul><ul><li>The key thing for James and pragmatism is that of an idea “working” </li></ul><ul><ul><ul><li>If believing that there is a gaping hole in the middle of the cafeteria prevents you from falling and breaking a leg, or making a fool of yourself in front of that cute boy from chapel, then that belief works. It is “true.” </li></ul></ul></ul>