I'm trying to write a paper about US Invasion in Iraq is unjust morally, militarily, and legally. I can't think of words to explain when I'm trying to explain that I have moral "evidence" or ideas from the book that will help to support my moral argument. It is technically not evidence, but what word should I use to accurately explain it like evidence?
An argument normally involves two opposing positions. If the argument is about factual matters, it's likely one or both positions can be either strengthened or weakened by evidence (as to which facts are true or false).
Thus, the US should not have invaded Iraq can be supported by facts (Iraq had nothing to do with 9/11, Iraquis are worse off now than under Saddam Hussein, they never had any WMD, etc.)
If the argument involves opposing moral positions, "facts" aren't necessarily relevant. A sound moral argument is based on principles (any use of military force is wrong, nations should not interfere in the internal politics of other nations, etc.).