Cogency: Encyclopedia - Cogency

Cogency

An argument is cogent if and only if the truth of the argument's premises would render the truth of the conclusion probable (i.e., the argument is strong) and the premises are, in fact, true. Cogency can be considered inductive logic's analogue to deductive logic's "validity." As an example, consider the following.

The truth of the premises would, indeed, make the conclusion probable. Therefore, this argument is strong. If the premises are, in fact, true, then the argument is also cogent.

Cogency - Probable

There is no standard of how likely an event must be for it to be called "probable." Just as there are degrees of probability, one can also speak of degrees of cogency. The degree of an argument's cogency, then, is a function of the argument's strength. In the above example, Jill pulling out a 101st marble that turns out to be red would make the conclusion even more likely, and therefore the argument stronger. Note that this feature of cogency is a disanalogy from deductive logic's "validity," since a deductive argument can be either valid or invalid and nothing in between.

Cogency - Good argument

Good argument, as used by philosophers and many others, means simply a sound or cogent argument. If one has offered a sound or cogent 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.

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

• Explanation
• Inductive reasoning
• Soundness
• Validity

Category: Logic

Adapted from the Wikipedia article "Cogency", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki