Throughout all your college education, and elsewhere when educated presentations are required, you must always see that your argument is aligned with the content. That is, if you want to prove some fact that we can see with our own eyes, things in the world around us, you must use inductive arguments. You prove a medicine works by testing it rigorously–that is inductive proof. But if you want to prove something that is necessarily true in all possible worlds, something that must be true because of the meanings of the words, the ideas, then you must use deductive arguments. You prove any person always has $4 if they have $2 in each hand, merely by thinking about it (you don’t have to see every case with your own eyes). So when you want to prove something, you must use induction for knowledge of our visible world, and deduction for knowledge of ideas (in all possible worlds). You cannot prove Smith shot Jones just by thinking about them–you have to have visible facts you can look at, touch, etc., from CSI (induction). But to know what murder is, what counts as murder, we must think about the idea, and how the word is properly used (deduction). A jury must decide both (what happened and whether that falls under the law), so both kinds of proof are presented to them. (We decide Smith shot Jones by induction, but call it murder by deduction (what the word means in law).