* we've discussed deductive argument validity and soundness; * now let's discuss inductive argument strength and cogency * inductive STRENGTH - is an inductive argument STRONG * a LITTLE trickier than determining deductive argument validity; (because of the nature of inductive arguments) * but some guidelines include: * as for deductive arguments, we look at the LOGICAL FORM of th argument, and do not yet concern ourselves with whether the premises are actually true; * key question: IF the argument's premises were true, WOULD the conclusion PROBABLY be true? * that is, a STRONG inductive argument needs to have a PLAUSIBLY BELIEVABLE logical structure * inductive COGENCY - * a COGENT inductive argument needs to be: * STRONG (have a strong logical structure) * AND the argument makes statements that are true in "real life" * this can include "making sense" to us based on our own knowledge and experience * this can vary from person to person ******* so NOTE: ******* * do you see that: * for a DEDUCTIVE argument: it might be INVALID and UNSOUND or VALID and SOUND or VALID and UNSOUND * can't be INVALID and SOUND, because to be even considered as SOUND, a deductive argument must first be VALID p. 80 of course text: deductive arguments / \ Valid Invalid (ALL of these are UNSOUND) / \ Sound Unsound * do you see that: * for a INDUCTIVE argument: it might be WEAK and NOT COGENT or STRONG and COGENT or STRONG and NOT COGENT * can't be WEAK and COGENT, because to be even considered as COGENT, an inductive argument must first be STRONG p. 80 of course text: inductive arguments / \ Strong Weak (ALL of these are NOT COGENT) / \ Cogent Not Cogent * ONE of our Chapter 3 patterns of deductive reasoning is Categorical Syllogism * a 3 line argument in which each statement begins with ALL, SOME or NO * in Chapter 9 - Categorical Logic -- we will give us TOOLS for better judging the VALIDITY of categorical syllogisms (remember, then, that's judging their logical structure)