12.1 WHAT IS A GOOD ARGUMENT?
We have discussed different aspects of arguments. It is time to consider how they help us explain what a good argument is. Intuitively, a good argument is one in which the premises provide good reasons for the conclusion. This is of course quite vague. Let us try to make it more precise.
Condition 1: The premises are true or highly plausible
The premises of a good argument must be known to be true, or they have to be at least highly probable. This criterion should be rather obvious. We have no reason to accept an argument if the premises are false or are unlikely to be true.
Condition 2: The argument is deductively valid or inductively strong
Deductively valid arguments are of course valuable. Valid arguments cannot lead us from true premises to false conclusions. But we have seen that inductively strong (and hence invalid) arguments play an equally important role in reasoning. It will be too restrictive if we demand that all good arguments must be valid. We would have to give us most of our scientific knowledge. Note that if a good argument is either valid or inductively strong, this implies that an inductively weak argument can never be a good argument.
Condition 3: The premises are not question begging
The first two conditions are still not sufficient for a good argument. Consider this circular argument, where the conclusion appears as a premise:
This is surely a bad argument since no independent reason has been ...