Logic (Greek: logos = "word", "speech", "reason") is the science that evaluates valid reasoning within arguments. That's it.
Many people think logic refers to a lot more than just that. However,
Logic is not a set of laws that governs the universe - that's physics.
Logic is not a set of laws that governs human behavior - that's psychology.
Logic is no a method for 'studying the world', that's science.
Logic is not the method for assessing axioms, that's a matter of pure reason.
Logic is not a way of evaluating 'truth' - that's philosophy.
Logic is not transcendent or immaterial - that's incoherent, as these terms have no ontological status, i.e., no positive way of identifying them.
Logic is simply a set of rules, created by sentient beings, meant to tell us when an argument 'works', i.e., when an argument supports the conclusion the arguer wants to make.
In short, a logical argument produces a true conclusion, if we pour true premises into it. That's it!
Reasoning 101: What matters in the end is whether the reasoning is sound; justifying the premises, and whether the argument form is valid; proper inference.
When a an argument is deductive, valid and sound, its conclusion is true no matter how disturbing, how counter-intuitive, how emotionally unsatisfying the conclusion. http://www.iep.utm.edu/f/fallacy.htm