Ham. Do you see yonder cloud that ’s almost in shape of a camel?One of the things that I think is essential for rational thinking, is being aware of how we think. And as much as rational thinking is scorned and ignored (seriously, read the news sometimes) I do think it's an essential part being a citizen - figuring out what you want your society to be like, being able to step back look at what is involved, what information you have available, what actions can reasonably be expected to produce the desired result and make a decision.
Pol. By the mass, and ’t is like a camel, indeed.
Ham. Methinks it is like a weasel.
Pol. It is backed like a weasel.
Ham. Or like a whale?
Pol. Very like a whale.
Hamlet. Act iii. Sc. 2. William Shakespeare (1564–1616)
So knowing how we think is important. And if you spend any great length of time studying the way we think, or any length of time at all really, one of the things that you will notice is that we all have bias, assumptions are made, arguments are used to attempt sway other people that are somewhat ... dubious. Information is beautiful have composed a quite comprehensive list of rhetorical and logical fallices that are commonly used. Stop, take a moment and go read it over. Please. Forward it to others. Make sure they read it. For two reasons - it would be nice if people stopped using these (a lot of people I suspect use them with out being aware of the flawed nature of the argument they're using) and people really really need to be able to identify when these are being used in an attempt to sway them - many of these are used daily by politicians, religious leaders and woo-meisters.The straw man is beloved of politicians everywhere. Journalists appear to be quite fond of Cum hoc ergo propter hoc and Post hoc ergo propter hoc. Conspiracy theorists are fond quite fond of circumstance ad hominem.
The list isn't perfect. There's a couple there that I would re-word - Appeal to ridicule is one. Sometimes ridicule is the only tool available. When numerous flaws in logic have pointed out and an opponent refuses to budge, ridicule becomes justified. Maybe not very nice, but justified. Like when someone brings up homoeopathy*. That aside, it is always a good thing to step back from any case being presented to you and looking at who is presenting it, and what their interests are. Then look at the case they have presented are and try and find the flaws. Finding the flaws (or lack of them) will tell you significantly more than listening to a case uncritically.
I'm not perfect, I probably still commit a few of these fallacies, but I am getting better at identifying when they are presented to me. Picking out patterns of speech, specifically looking for the fallacies. Modelling systems helps - when you are modelling complex systems, you are necessarily making assumptions and you have to continually look back at your assumptions every time you get a new piece of data and review everything, just to make sure your assumptions are still valid - it's time consuming and laborious but necessary if you want to know what is rather than what you think should be.
*which all evidence points towards being no better than placebo at relieving symptoms - not underlying conditions and involves all sorts of ethical problems, a post for another day.