Fallacies

•          Fallacies

–        A fallacy is an error in reasoning that results in an invalid argument

–        Three common fallacies:

•          Vague or ambiguous premises

•          Begging the question (assuming what is to be proved)

•          Jumping to conclusions without adequate grounds

–        Converse Error:

•          Premises: p à q and q, conclusion: p

–        Inverse Error:

•          Premises: p à q and ~p, conclusion: ~q

–        It is possible for a valid argument to have false conclusion and for an invalid argument to have a true conclusion:

•          Premises: if John Lennon was a rock star, then John Lennon had red hair, John Lennon was a rock star; Conclusion: John Lennon had red hair

•          Premises: If New York is a big city, then New York has tall buildings, New York has tall buildings; Conclusion: New York is a big city