READING #3 “BELIEFS, PROPOSITIONS, AND TRUTHS” By Robert FitzGibbons from Making educational decisions: an introduction to Philosophy of Education (New.

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Presentation transcript:

READING #3 “BELIEFS, PROPOSITIONS, AND TRUTHS” By Robert FitzGibbons from Making educational decisions: an introduction to Philosophy of Education (New York & London: Harcourt, Brace Jonanovich, Inc., 1991)

Propositions are statements of belief which are either true or false. eg. p = “Children are by law compelled to go to school.” - “X believes that p”, where p is a proposition. - X assents to the truth of the proposition p. The degree of assent can vary from very strong to quite weak. Propositions and Truths p. 40 “Having a belief, then, is tantamount to affording some degree of psychological assent to a proposition. And the proposition, with which this assent is associated, is either true or false; it cannot be both.” - “The truth or falsity of a proposition is not dependent on anyone's believing it.” eg. The truth of the proposition “The earth is not flat” is not dependent on whether anyone believes it. As you know, a short time ago, relatively speaking, the earth was believed to be flat.

P. 41 Common misconceptions regarding the relativity of the truth of beliefs: (1) “Any proposition is both true and false at the same time” (2) “The truth of a proposition may change over a period of time” (1)Note disproof of (1) – P. 41 (middle) ** Self-contradiction ► Let q = “Any proposition is both true and false” ► If q is true, then any proposition is both true and false ► However, q is itself a proposition. ► Hence, if q is true, it follows that q is false. ► And if q is false, then it is not the case that any proposition is both true and false. Self-contradiction: Thus, “q implies its own negation. It is inherently contradictory.” Note: Only one counter-example is necessary and sufficient to disprove a proposition.

Common confusion lies in the comment: “What is true for you may not be true for me.” ► “failure to distinguish between a person's believing something and what that person believes” The propositions: “You believe p is true” and “I believe p is false” are not inconsistent. They may be both true at the same time. But remember, the fact that someone believes p to be true does not make p true. Note the incorrect inference on P. 43 (middle).

(2) “The truth of a proposition is atemporal.” If p is true today, it was true in the past, and will also be true in the future. P. 44 “Time, then, is not relevant to the truth (or falsity) of a proposition unless the proposition explicitly or implicitly makes reference to a period of time. Even if there is such a time reference, time can in no way affect the truth of the proposition.” Note: 'Water in glass' ex. P. 44 (bottom half) – implicit time reference; a different time reference means a different proposition. Truth and Proof P. 46 “Many … confuse the truth of a proposition with the proof of a proposition. They believe that if a proposition cannot be proven true, then it is not true; or that then it is neither true nor false.” Problem: Many do not understand just what a proof is.

P. 46 “A proof does not make a proposition true; it merely exhibits or demonstrates the truth of a proposition. It discloses what is already there.” Note: Analogy of 'coin under chair' P. 46 (bottom) “Truth does not come through proof, nor is it necessarily absent in the absence of proof. If a proposition is proven to be true, it was true prior to the provision of the proof and would have remained so had no proof been given. Again, a proof only demonstrates or discloses the truth of a proposition.”