Critical thinking is a mental process of identifying what you actually know and what is assumption, what is real evidence and what is mere assertion or faked. (It also deals with what is a valid or an invalid or fallacious argument, but I’ll just deal with the issue of evidence here.)
When someone makes a claim, but doesn’t tell you their evidence for that claim, it’s good to point out to that person that he hasn’t presented sufficient evidence to convince you of his claim. “Sufficient evidence” includes telling you where he got that evidence – the source – of the information, so that you, too, can go to the source and evaluate whether it is a “primary” and reliable source.
For example, there has been a screen capture, purportedly of a Facbook page, being used in discussions about the character of Trayvon Martin, the young man who was shot and killed in a physical fight with George Zimmerman, a neighborhood watchman in a gated community in Florida. This capture is being used as evidence to show that Trayvon was a user of a drug mixture called “lean” which can make some people paranoid and aggressive.
The capture shows Trayvon’s photo with the name “Trayvon Slimm Martin” having a discussion with another young man about the ingredients of lean, clearly with the aim of getting the ingredients together and using it.
Many people seem to believe that that capture is evidence you can count on. But with Photoshop, I’m pretty sure that I could create such “evidence” myself, if I could find a conversation about lean on someone else’s Facebook page, make a screen capture of it, go to Martin’s Facebook page and screen capture a conversation between him and a friend, then copy and paste Trayvon’s and a friend’s photos and names over those of the people who were *really* having the naughty conversation.
Now, one could seek out “Trayvon Slimm Martin” on Facebook, which I’ve tried to do, and check to see that the discussion is on a real Facebook page. (I’ve tried. If the page once existed under “Trayvon Slimm Martin”, I can’t find it now.)
But even if I found such a page, I’d have to somehow verify that it belonged to *the* Trayvon Martin in question, that someone else faking that name (or who actually shares that name) didn’t just lift a photo of the famous Trayvon because he thought it would be “cool”. That is not a farfetched possibility. Those kinds of fakes are easy and some people love to do that kind of thing.
Critical thinking requires a person to be aware of when alleged evidence hasn’t yet been *proven* to be evidence, and to make yourself aware of what it would take to actually prove it to be evidence. Until you can see for yourself that it is true, you should not accept it as such. One needs to keep oneself aware of the actual status of an alleged piece of evidence in your context of knowledge.
Someone else may know it to be true, but they have to help you to know that it’s true, from the evidential source and through sound reasoning, or they should not expect you to accept their claims.
One of my points in my earlier post is that this is not an easy task, and even the most conscientious people make errors, sometimes accepting alleged evidence too soon.
I say “Conscientious people, unite!” We should all happily help each other in a friendly way to be strict in our critical thinking. And, because critical thinking is so important to such things as justice, we should do what we can to help those with really bad thinking habits to develop better ones by patiently pointing out errors and showing, by example, how critical thinking works.
I say “patiently” because if you treat a person with impatience it’s like saying “Don’t you know this already? How could you make such a mistake? Why aren’t you getting this without my help? You must be a stupid fool.” So instead of focusing attention on the issue at hand and creating an atmosphere conducive to an objective examination of facts, you’re setting up the other person to feel defensive. Now he feels like he has to defend his character and intelligence and feels all emotionally stirred up. I hate seeing that happen when something constructive could actually be happening instead.
Whether it’s an error made by a habitually conscientious mind, or an error made by someone with horrible thinking habits, if you make the effort to address the error without attacking the person making it, you’re offering a small contribution toward making the world a more just and reasonable place.