Fallacies Flashcards
affirming the consequence
even if both premises are true, they do not guarantee the truth of the conclusion
petitio principii
begging the question, tactic of assuming what you need to prove
ad hominem
instead of criticising claim, criticise person making it
equivocation
same term is used variably in different parts of the argument
post hoc, ergo propter hoc
‘correlation does not imply causation’, inferring that something is responsible for something else because the former precedes the latter
retrodiction
reasoning from the present to the past
direct inference
reasoning from populations to samples
induction-to-causes
reasoning from effects to causes
induction-to-unobservables
reasoning from observables to unobservables
instance-to-the-next-instance
reasoning from one or more observed instances to the next instance
enumerative induction
reasoning from one or more particular instances to all instances
disjunction introduction
A, therefore A or B
conjunction elimination
A and B, therefore A
disjunction elimination
A or B, not A therefore B
what do truth tables show?
validity and consistency
a posteriori
knowledge based on facts/past events
modus tollens
if A then B, not B therefore not A
modus ponens
if A then B, A therefore B
reductio ad absurdum
proposition disproved by following implications to logically absurd conlusion
negation elimination
removes double negatives
contraposition
if A then B, not A therefore not B
necessary condition
something which must be present for another condition to occur
sufficient condition
something which produces said condition
conditional proof
something which proves if A then B
reasoning by contradiction
proves proposition by showing that assuming proposition is false leads to contradiction
circular reasoning
fallacy in which reasoning begins with what are trying to end with
law of non-contradiction
contradictory propositions cannot both be true in the same sense at the same time
logical equivalence
two statements with the same truth values for every intrepretation
synthetic statements
opposite of analytic, any statement which cannot be determined by linguistic meaning alone
even if both premises are true, they do not guarantee the truth of the conclusion
affirming the consequence
begging the question, tactic of assuming what you need to prove
petitio principii
instead of criticising claim, criticise person making it
ad hominem
same term is used variably in different parts of the argument
equivocation
‘correlation does not imply causation’, inferring that something is responsible for something else because the former precedes the latter
post hoc, ergo propter hoc
reasoning from the present to the past
retrodiction
reasoning from populations to samples
direct inference
reasoning from effects to causes
induction-to-causes
reasoning from observables to unobservables
induction-to-unobservables
reasoning from one or more observed instances to the next instance
instance-to-the-next-instance
reasoning from one or more particular instances to all instances
enumerative induction
A, therefore A or B
disjunction introduction
A and B, therefore A
conjunction elimination
A or B, not A therefore B
disjunction elimination
validity and consistency
what do truth tables show?
knowledge based on facts/past events
a posteriori
if A then B, not B therefore not A
modus tollens
if A then B, A therefore B
modus ponens
proposition disproved by following implications to logically absurd conlusion
reductio ad absurdum
removes double negatives
negation elimination
if A then B, not A therefore not B
contraposition
something which must be present for another condition to occur
necessary condition
something which produces said condition
sufficient condition
something which proves if A then B
conditional proof
proves proposition by showing that assuming proposition is false leads to contradiction
reasoning by contradiction
fallacy in which reasoning begins with what are trying to end with
circular reasoning
contradictory propositions cannot both be true in the same sense at the same time
law of non-contradiction
two statements with the same truth values for every intrepretation
logical equivalence
opposite of analytic, any statement which cannot be determined by linguistic meaning alone
synthetic statements
