I recently had an argument with a friend (an IEI) about whether or not 1+1 always equals 2. My argument was basically for 1+1 to not equal 2, you would need to change the definition of either 1, +, =, or 2 to get a different answer. He basically said that there is always room for doubt and nothing is absolutely true all the time. He then accused me of having too much faith in the system that I have been "forced" into and that I need to expand my mind, but I countered that I didn't need faith because if someone wanted to prove that 1+1=2, they wouldn't have a very hard time, unlike someone who was trying to prove that 1+1 could equal anything else. I'm sure you can assume that we were not in our right minds at the time, but I'm still irritated by what he was trying to force upon me. I kinda had flashbacks of 1984, like he was trying to convince me that 2+2=5.
Anyway, I'm using this as what I would consider an example of an argument against because I'm having trouble differentiating between the two. Feel free to add anything and/or provide your own examples.