Good argument, as one sees it used by philosophers and many others, means simply a
sound or else a
strong argument. If one has offered a sound or strong argument in defense of one's conclusion, then one has stated a
true view, or at least a
probably true view. The premises of one's argument
support, or, with some sophisticated complications aside,
justify one's belief in the conclusion. That is why good arguments are so important: a good argument is the closest thing we have to a guarantee that a belief is true. If one is armed with a good argument, one has helped to justify one's belief in the conclusion, and to
remove doubts about it.
See also validity; cogency; soundness.