Next to being logically sound, your reasons, or EXplanation, needs to make sense to the people you’re trying to convince. This can often be tricky as time constraints do not allow you to fully work out an argument. In order to work around this you have to appeal to reasons that your public accepts, or at least is familiar with. If you do this, then the burden of further supporting your argument will be less, than when you appeal to reasons that your public doesn’t accept at first hand. The expalantion is simple if your public accepts a reason or is familiar with that particular reasoning, then they will automatically fill in the blanks so to speak and complete the argument for you. This way you don’t have to explain your statement and then continue explaining your explanation.
The advice is thus, know your audience. More specifically know their belief system. A belief system is the network of interrelated beliefs that a person has that collectively makes sense of how that person beliefs the world is. In philosophical terms, a belief is a statement of how the world “is”. In an ideal case these interrelated beliefs support each other, but often not all of them do. If you know a person’s belief system, then you can appeal to those beliefs and immediately have much of their belief system helping you subconsciously to support your argument.
Take an easy example. Suppose you are talking to a socialist public about progressive income tax systems. If you then argue that a progressive tax system is fair, then your audience will subconsciously add their whole conceptual framework of fairness to your argument, without you having to. If on the other hand your trying to convince hard-core republicans that a progressive tax system is fair, then you will need to upset their entire belief system, which will be hard work.
What to do then if you’re faced with an audience that doesn’t support your line of reasoning at first hand. In that case you try to appeal to another belief in their belief system and show them how that belief actually supports your argument. In this way you use the fact that almost no belief systems people have fully justify each other. But make no mistake, this will still be very difficult, because people will try to keep their belief system intact. This will require you considering their emotions and Ego as well, but that is where Pathos comes in. At least from a Logos point of view, this will give you a fighting chance.
Suppose you are trying desperately to sell your progressive tax system to your republican audience. In order to do that you need to appeal to some belief that they hold. For example, that hard work should be rewarded. If you can then establish that although the market assigns value to work in an optimal way, this nonetheless results in some hard work not being fully rewarded, then you have your foot in the door so to speak. It’s still going to be very difficult, but again at least you have a fighting chance.
So the recipy for being able to use the right reasoning to support your arguments is making sure you know your audience well. But what if you don’t know your audience, or your audience is very mixed, what type of reasons do you then use? In that case the 17th century philosopher John Locke gives some advice. He argues that there are 4 generic types of acceptable reasons one can give with the first being most convincing and the last being the least convincing:
1. Natural (Scientific) laws: e.g. gravity
2. Common knowledge: e.g. pyramids are from Egypt, dinosaurs roamed the earth
3. Generally accepted beliefs: e.g. torturing innocent children is bad, genocide is bad
4. Personal experience: e.g. it’s becoming increasingly unsafe in the streets
Now we have to see this through the eyes of someone from the 17th century who still believed that the natural siences provide us with objective irrefutable certainty. Although the natural laws have become less credible then they once were, its still a pretty safe bet people will accept those as valid reasons, with the obvious exception of evolutionairy arguments in certain religious circles.
As we move down the list chances become less that your audience will accept them. However, if those reasons DO appeal to your audience’s belief system, then they can be as powerful as natural laws. An audience filled with UFO spotters (personal experience), will often accept the existence of alien life on our planet over natural laws. The same goes for an audience filled with victims of violent crimes. Good luck convincing them that statistics show violent crime is down.
Nevertheless this list does give you some handle on the type of reasons you can use and their ‘objective’ force in a debate. Scientific laws are more ‘objective’ than personal experience and thus more likely to be accepted by your audience. But in the end knowing your audience and appealing to their belief system is more powerful.