This type of argument is constructed by first defining the criteria or specific factors by which the issue being discussed is going to be judged against. It differs from comparative reasoning in that the issue is discussed by its own merits, and not in contrast with another similar item. As a result, it is necessary to spend a lot more time building the argument by establishing the validity and applicability of the criteria, though in a less formal setting the criteria can be assumed and you may not need much in the way of discussion about them beforehand.Â
An example:
Tammy and Jeff are shopping for a new car. Jeff wants to convince Tammy that they should buy a hybrid SUV. He sets up the criteria he believes they should look for when choosing a car: their family is growing, so they will need space. They want to keep running costs down and both care for the environment, so fuel efficiency and carbon emissions will be important. Lastly, Jeff likes to go camping off the beaten path, though Tammy just can’t stand it. Jeff then convinces Tammy that the car should be off-road capable by appealing to her desire to see him happy.
Using common values is the best case you can use, because if you and your opponent do not share those you will have to first convince them to accept those, which will take even more time. You may have to use other criteria to select those criteria, and others to select those in turn, and so on and so on.
This is a weakness of using this type of reasoning: at some point you will have to either have some form of common bedrock from which to argue, or resort to other, more robust and independently founded forms of reasoning.
Its strong points are that if the criteria are well-founded and held in common, they can then be used as a foundation for future arguments, and the precedent set in the first discussion may further be used for comparison. A sound set of criteria also makes your argument much more difficult to argue against, particularly if it appeals to common ideals.
