Presentation on theme: "Introduction to Philosophy Truth, Postmodernism & Pluralism By Professor Christopher Ullman."— Presentation transcript:
Introduction to Philosophy Truth, Postmodernism & Pluralism By Professor Christopher Ullman
10 Truths about Truth 1. A statement is true if it corresponds to reality, and a statement is false if it does not correspond to reality. 2. All truth claims are absolute, narrow and exclusive. 3. Truth is discovered, not invented. It exists independently of anyone’s knowledge of it. 4. Truth is indispensable for living. Consider the need for truth in matters relating to safety, money, relationships, transportation, and court proceedings. 5. Beliefs cannot change a fact. 6. Truth is trans-cultural. 7. Being raised in a given culture doesn’t make the beliefs of that culture true. 8. Truth is not affected by the attitude of the one professing it. 9. Contrary beliefs are possible, but contrary truths are not possible. 10. We can believe everything is true, but we cannot make everything true.
Think about these 10 statements, then … Ask yourself, “What if even one of these statements was not true? How would that change the way I think?”
The Three Laws of Rational Thought The Principle of Identity: “It is what it is.” One must be able to say, “If a thing is A, then it is A”. A thing (object, person, entity, concept) cannot continue to exist and at the same time cease to exist. Examples: A = A If it is a cat, then it is a cat. If Springfield is the capital of Illinois, then it is true that Springfield is the capital of Illinois.
The Three Laws of Rational Thought The Principle of Non-Contradiction: “It is not what it isn’t.” One must be able to say, “If a thing is A, then it is not non-A”. A thing (object, person, entity, concept) cannot be itself and its opposite, in the same sense at the same time. Examples: A non-A If it is a cat, then it is not a non-cat. If Springfield is the capital of Illinois, then it is not true that Springfield is the non-capital of Illinois.
The Three Laws of Rational Thought The Principle of the Excluded Middle: “It either is or it isn’t.” One must be able to say, “A thing is either A or non-A.” A thing (object, person, entity, concept) must be either exactly as it is described or not. Examples: Either A or non-A It is either a cat or it is a non-cat. Either Springfield is the capital of Illinois or it is not the capital of Illinois.
These Three Laws make it possible for you to speak or write a statement, and expect it to be: Understood, and Accepted, or Rejected, or Shelved, awaiting more information Each truth claim must be either 1. Accepted for sufficient reasons 2. Rejected for sufficient reasons 3. Shelved with judgment suspended, pending the investigation of reasons for and against it.
What cannot happen, if one intends to be rational, is to respond to a truth claim in these ways: “That may be true for you but not for me.” “Everything is merely an opinion, and each opinion is as good as another.” “You can believe it’s up, and I can believe it’s down, and we can both be right.” “If you think it is, then it is. If you think it isn’t, then it isn’t. It’s all in a person’s mind.”
A Postmodernist’s Creed “Nothing is certain.” “Nobody knows anything for sure.” “Everything ought to be doubted.” “What is true for you may not be true for me.”
“Nothing is certain.” Is this statement certain? a. If so, it contradicts itself, since one thing is certain: that nothing is certain. b. If this statement isn’t certain, why is it stated in such certain terms? It’s wording doesn’t convey a sense of uncertainty about its truth. The postmodernist apparently is certain about this. See a. c. Either way, I must conclude that this statement is false.
“Nobody knows anything for sure.” Can I know this for sure? a. If I can know this for sure, then the statement contradicts itself. b. If I can’t know this for sure, then why is it stated so surely, in such forceful, confident language? It seems as if the postmodernist believes this to be a certainty. See a. c. Either way, I must conclude that this statement also is false.
“Everything ought to be doubted.” Does this include the statement, “Everything ought to be doubted?” a. `If it does include the statement “Everything must be doubted,” then I must doubt that everything ought to be doubted. I will either end up rejecting the statement or accepting it.
“Everything ought to be doubted.” (continued) If I refuse to doubt the above statement, I will be creating a “DO NOT DOUBT!” box. “DO NOT DOUBT THIS!” If I put anything in this box, I refute the above statement! “Everything ought to be doubted.”
“Everything ought to be doubted.” (continued) If I decide to doubt the above statement, What criterion will I use to determine if the statement can survive my doubting process, and become a certainty? Choosing any criterion establishes something objective that cannot be doubted. This refutes the above statement. “Everything ought to be doubted.” If I can’t find a criterion, I can’t start doubting! Either way, I must conclude the above statement is false.
“What’s true for you may not be true for me.” Obviously, this statement must apply to itself, as well as to all other truth claims. If so, then the above statement is true for you, but not necessarily for me. So, if it’s not true for me, then I must be open to the idea that some things that are true for you are also true for me. There must be a jointly held “truth box” we both can access. How we decide what belongs in it requires criteria we can both agree about. The criteria become some things that are both true for you and true for me, and for everyone. This means the statement above is false.
Self-referential Incoherence This occurs when a statement cannot be true if it is applied to itself. All four of the Postmodern Creed truth claims are this way. The only way they can be true is if they are false. This results in a self-contradicting set of beliefs. The Law of Noncontradiction is essential to rationality. Therefore, this Postmodernist’s Creed is irrational.
The truth is: There must be truth. This truth entails (requires) Criteria for evaluating truth claims Minds to do the evaluating tasks If you are reading this, it means you have a mind, and are capable of evaluating truth claims using criteria, and we can continue for a bit longer in this discussion.
Criteria What are they? 1. Standards on which a judgment or decision may be based 2. Characterizing marks or traits Why are they needed? To answer these questions When we say something is true, what convinces us? How can we hope to convince others?
Four Major Groups 1. Immediate criteria 2. Social criteria 3. Philosophical criteria 4. Revelation
Immediate Criteria 1. Instinct - "My instincts tell me this is true." 2. Feeling - "My gut tells me this is true," or "I can feel it in my bones." 3. Sensed experience - "My senses tell me this is true." 4. Intuition - "It came to me in a flash!"
Social Criteria 1. Custom - "It is our custom to say this is true." 2. Tradition - "For generations, we have held this to be true." 3. Universal agreement (consensus) - "Everyone knows this is true."
Philosophical Criteria 1. Correspondence - "This idea corresponds with reality, so it is true." 2. Pragmatism - "It works, so it must be true.” 3. Coherence - "It is systematically consistent with what has been found to be probably true, so it is probably true."
Revelation Divine revelation - "It is true because God has said in the Scriptures that it is true."
A Question Which criteria can serve as the final court of appeal? Probably only revelation
Why revelation? The revelation criterion presupposes 1. A perfectly intelligent being to whom all truth is known 2. That this being has self-disclosed 3. That this being values truthfulness If these three presuppositions are true, then 1. Divine revelation will stand as the ultimate arbiter of all truth- claims 2. Nothing that can be called "true" can possibly contradict this revelation
Religion and Truth 1. No one follows a religion that s/he believes to be false 2. Confidence in the truthfulness of one’s religion is important 3. Truth claims build belief systems for the religion’s adherents 4. Truth claims can be based on several different criteria at once Each truth claim must be either 1.Accepted for sufficient reasons 2.Rejected for sufficient reasons 3.Shelved with judgment suspended, pending the investigation of reasons for and against it.
Different uses of “knowledge” A. I know how to ride a bicycle. B. I know that it is cold outside. C. I know my A, B, C’s. D. I know my friend John very well. E. I know that he would not lie. F. I know my next-door neighbor. Group this into similar ways of using the word “know.”
Different uses “knowledge” Knowledge by acquaintance. I know my friend John very well. I know my next-door neighbor. Knowledge how I know how to ride a bicycle I know my A, B, C’s. Knowledge that (propositional knowledge) I know that it is cold outside. I know that he would not lie. Philosophers have tended to focus on “knowledge that,” propositional knowledge.
What does it mean to “know” something? In order to know something, one must believe that it is true. One can’t know something that one does not believe. (Believing is a necessary condition for knowing.) For example: Imagine that I don’t believe that George Bush in the President of the U.S. If this is true, I could not be said to know that George Bush is the President of the United States. One can believe something that one does not know. (Believing is not a sufficient condition for knowing. For example: Imagine that on the basis of a vague horoscope message for the day, I believe I will win the lottery. I believe it, but I do not know it.
Belief is a necessary, but not a sufficient condition for knowledge:
What does it mean to “know” something? In order to know something, the thing I know must be true. One can’t know something that is false. (The truth of the proposition known is a necessary condition for knowing.) For example: I cannot know that John Kerry is the president of the U.S. A proposition can be true without my knowing it. (The truth of a proposition not a sufficient condition for knowing it.) For example: Imagine that it there are 200 patients at Finley Hospital right now. The fact that this is true does not mean that I know that it is true.
Truth is a necessary, but not a sufficient condition for knowledge:
True beliefs could be diagrammed like this:
What does it mean to “know” something? True beliefs may not be knowledge: For example: Imagine that every Monday I wake up with the belief that I will win the lottery. I have never won the lottery in my life, in spite of the fact that every Monday I believe I will. Imagine that I do win the lottery today. Did I know I would? My belief is true, but it is not knowledge. The problem is, I did not have a good reason for my belief, I wasn’t “justified” in my belief.
Only justified, true beliefs are cases of knowledge:
But what does it mean to say that a belief is justified? Descartes was looking for evidence that the belief could not be false, for absolute certainty. (Infallible justification) Although Descartes didn’t think so, most philosophers today believe this results in skepticism. Alternative: Justification can be fallible. One can have good reasons or evidence without absolute certainty.
Three kinds of knowledge Acquaintance knowledge I know Oxford. Ability knowledge I know how to ride a bike. Propositional knowledge I know that elephants are heavier than mice.
Justified true belief Analyses knowledge in terms of necessary and sufficient conditions ‘I know that p’: The proposition ‘p’ is true; I believe that p; and My belief that p is justified.
Necessary and sufficient conditions Each condition is necessary for knowledge. The three conditions together are sufficient for knowledge.
The appeal of Justified True Belief I can’t know what is false. I can’t know a proposition that I don’t believe to be true. Beliefs that are irrational or aren’t based on the evidence aren’t knowledge.
Objection Is this enough for knowledge? Or should we consider what the facts might have been? That’s Judy! Case 1: Meeting Judy That’s Judy! Case 2: Meeting Trudy
Development Condition 4: My justification for believing that p ‘stands up to the facts’. I know that p if my justification for believing that p is ‘undefeated’.