TL;DR Dont' be a dick.
I have fairly strong views on many subjects. So, typically, as someone who uses the internet, I end up, often against my will, being dragged into debate, after debate, after debate.
I enjoy proper debates, they challenge what I know, not just about other peoples positions and views, but perhaps more importantly my own. Not only do I want people to challenge me, I expect people to.
However, there's a problem. Most people don't know how to have a proper debate anymore. Here's why...
Control your emotions (ad hominem)
This is probably the most common offence when it comes to people attempting to have a debate. They don't understand the difference between a debate and an argument. A debate is where two people, exchange and discuss ideas in a polite and civilised manor. An argument is a confrontation, according to the dictionary... "an exchange of diverging or opposite views, typically a heated or angry one". Sometimes when I get into a debate with someone my age, it feels like they've just entered a rap battle.
Now you might point out that other peoples views, especially ones which you deem to be 'wrong', might make you angry. But if you understand why that argument is wrong, or foolish, then you should have no problem explaining to that person in a polite way, how they are wrong.
If you resort to getting angry, swearing at them, then it's usually a sign that you either can't explain to them why they are wrong, or you can't explain to them why you are right. Anger during a debate, typically means that person has lost the debate.
But what of people who are openly being racist? Or people who are ardent Mao supporters? This should be no different, in fact, they are so obviously in the wrong, that you should find it even easier to politely put them in their places. You have picked an easy battle here.
Okay, so what if you've made countless polite counter points, but the other person just isn't listening, or is themselves being rude and emotional. Then don't waste your time, you may never convince this person, you could throw facts and logical arguments at them for a thousand years, and you would still get no where. Back away, they're probably a lost cause.
Appeal to emotion
The second part of this, is people, tend to make emotional arguments when they're losing. For example, I spent a great deal of my time ardently sticking up for free markets on Facebook. The most common fallacy I tend to come across is the 'appeal to emotion' fallacy.
If I talk about free-markets, someone will say 'yeah, well, there's loads of homeless people on the streets, don't you care about homeless people?'. It's a bit of a cheap shot. Of course I care about homeless people, it's not relevant to the debate to just accuse someone of 'not caring' about 'x group of people'. You have to put about a reasoned argument as to why 'x will harm y'.
Another common use of this fallacy, is simply using emotionally loaded language.
Person a - I would like to deregulate the workplace for x reasons.
Person b - You capitalists just want workers to work in vile, despicable conditions, so's you can line your greedy pockets with filthy money.
Person b isn't really making a proper argument, person b is essentially just listing negative adjectives in the hopes the other person will just feel bad and agree with them. This is people who don't understand the subject, attempting to sound prophetic and caring by berating person a with intimidating, emotionally loaded language.
Watch your language
This ties into my last point, but if you're swearing, you're probably making emotionally loaded arguments, and you're probably trying to intimidate your opponent. Which means you don't know what you're talking about.
Don't reference experiences which are unique to you
By this I mean, sentences which start like 'I knew a guy once...' or 'my mum...' followed by some scenario that was unique only to a guy you knew once or your mum. Okay so an example:
Person a - 'State healthcare is often less efficient and cost effective than private healthcare'.
Person b - 'My mum was in hospital recently, and she said it was better than this time she was in a Swiss hospital'. This ties me nicely into my next point...
Appeal to authority
I had a debate on veganism once, where I made the point that it was perfectly healthy to live on a plant-based diet. The other person said something along the lines of 'My mum has this rare condition I don't know the name of, but if she went vegan, she would die, if you think I'm wrong, you can ring her GP'.
Asides from the obvious patient doctor confidentiality clause, one unique experience to yourself or someone you know, isn't a statistic. It's a trivial anecdote, and probably irrelevant.
Now I'm not doubting her mum did have this condition, and I don't doubt that her doctor did tell her this, but it's purposely made virtually impossible for me to research or refute this point. Not because it's true or a good argument, because I can't realistically go and check it's validity.
With the EU referendum just around the corner, I've been seeing entire memes being made of this fallacy
Someone took the time to create the longest 'appeal to authority meme' I've ever seen. They've cherry picked anyone remotely clever or powerful, disregarding vested interests, and context around each name given into a nice handy list. The purpose of this fallacy is to make the opponent feel as though he or she is isolated, and inferior to people who happen to share the view of that person.
This line of argument (or lack of...), is a lazy and disingenuous argument, i.e. not actually offering their own explanation. Often in these cases, the people they cite, bare scant relation with the subject of the debate. For instance, in this case, Stephen Hawkins is listed in the list of 'nice, clever people who share my view'. However, though he is a genius in his own field. He's not an economist, he hasn't studied ethics, or contemporary political theory as far as I'm aware.
The appeals to authority are usually cherry picked as well, that list has missed off countless relevant 'authorities' who are much better versed in this particular subject who would share the opponents position. I could name at least twenty, highly-esteemed economists who would be in the other column.
I touched on the briefly in my first point. But it's worth getting into a little more detail on. So what is a 'strawman' argument?
According to Wikipedia...
A straw man is a common form of argument and is an informal fallacy based on giving the impression of refuting an opponent's argument, while actually refuting an argument that was not advanced by that opponent.
Or for example...
Person A - We should privatise transport for x reason.
Person B - You want to stop poor people from using transport.
Person a has made an argument, but person b has twisted that argument to make b look cold and uncaring towards the poor. When actually person a might, and probably does believes that the poor will have better access to transport in the scenario he or she proposed. Also, person b hasn't explained why person a's proposal will hurt the poor.
Argumentum ad lapidem
According to wiki...
Argumentum ad lapidem (Latin: "to the stone") is a logical fallacy that consists in dismissing a statement as absurd without giving proof of its absurdity. The form of argument employed by such dismissals is the argumentum ad lapidem, or appeal to the stone.
Argumentum ad lapidem, or Appeal to the stone, is another very common fallacy when debating. Appeal to the stone is where someone dismisses and argument as 'absurd' or 'stupid' without actually explaining why that's the case.
Person a - We should leave (or remain, whatever) in the EU for x reasons.
Person b - That's all bullshit man.
Person a - Why is it?
Person b - Just is.
These people are lowest of the low, the most infuriating of all. Not just because of the abruptness and rudeness of their challenge, but because of the lack of proposition of their own argument.
This means this person has likely sculpted their opinions based on 'stuff they've seen on Facebook', or have based their thoughts on some ideal other figure without understanding. These people have usually based their views on someone else's views, without being able to back them up. This is typical of people who adopt views based on how fashionable they are at the time.
Thanks to Russell Brand, there has been an influx of people who vaguely support varying degrees of state collectivism, but can't really detail why.
'Something about the rich? 1% something? Wall street and bankers are mean... [insert ad hominem] [insert link to Russell Brand video] wake up man!'.
This is a very common fallacy. It goes a little something like this.
Person a - I want to leave the EU for x reasons.
Person b - You UKIP lot are wrong for x reasons.
Person b has erroneously assumed that person a is aligned to a specific euro-sceptic political party, which has other views not necessarily relating to the EU. This is usually done through sheer ignorance by person b, assuming that the only people making that argument are the political organisation most commonly associated in the media with person a's view. Or more commonly, it's asserted on purpose to make person a look as though they're aligned with some bigger, much less glamorous body of thought, in order to stigmatise person a.
Person a - I believe in communally owned means of production for workers.
Person b - You communists seem to forget that Stalin killed 20 million people.
This isn't exactly fair, because Stalin was a very specific, adaptation and implementation of communist theory, in which most self-confessed communists would reject.
Argumentum ad populum
This is a pretty simple, but common fallacy to spot.
Person a - I think we should legalise x for y reasons.
Person b - Most people think that's silly and dangerous, no one else thinks that.
This is another very lazy argument. It boils down to 'I can't explain why you're wrong, but I know loads of people who think you're wrong'. You only have to gently remind that person that, once 'loads of people' thought slavery was just dandy. It took a small minority of abolitionist thinkers a lot of convincing to change the consensus.
Consensus isn't always right.
Why should you take debate seriously?
Simple. Debate is progress. Whether it's for what programming language to use in your tech start-up, to what legal system a newly independent country should adopt. Everything pins on the underlying debate which fostered that action to take place in the way that it did. Without debate, we'd just be winging everything without prior, accountable thought.
It forces us to think laterally about a problem, to attempt to find truth in thought. It challenges our own views, it makes us more intellectually accountable.
So why is it important to conduct debate productively and politely?
Why shouldn't you make emotionally loaded arguments? Why shouldn't you insult people who don't agree with you? Firstly It doesn't matter how angry you are, or how emotional you are, it doesn't make you right.
Secondly, you want to create a conducive, inclusive, judgement free environment for debate. In other words, not a toxic environment where only certain people dare to tread. You should create a debate where anyone feels safe and unthreatened to join in.
In order to conduct productive debate, you must be polite and respectful no matter how much you disagree with the opponent. You shouldn't make it personal. You should be able to have a heated debate with someone, but step away still as friends at the end of it, having felt challenged and with a better understanding of your own views.