Argument and Philosophical Methodology
Argument: A set of at least two claims one of which is the conclusion. Any other claims in the set
are premises. The conclusion is the claim that one is trying to prove, and the premises are the
reasons offered in support of the conclusion
Valid Argument: An argument in which it is impossible for all of the premises to be true and the
conclusion false. In order words, if all of the premises are true, the conclusion MUST be true.
Invalid Argument: An argument intended to be deductive but with premises that fail to guarantee
that the conclusion is true. In an unvalid argument, the conclusion could be false even if all the
premises are true.
Sound Argument: A valid argument where all of the premises are true.
Unsound Argument: An argument which either contains a false premise, or is logically invalid, or
Moral Argument: An argument in support of a substantive moral claim.
Thought Experiment: An example developed to prove or disprove a particular claim or argument
or to persuade us of the plausibility of a thesis.
Counter Example: An example that is intended to counter a given claim or argument
Reflective Equilibrium: For many, it is the end point of a process of philosophical deliberation. It
involves going back and forth between principles and what they imply about specific cases to attain
a state of coherence or consistency among the moral principles we a