Inductive and deductive logic can both be studied with the formal tools we learn in this book. Our focus, however, will be on deduction: the notions of entailment and validity.

Our focus is **deduction**: entailment and validity.

The main reason why is that you have to learn deductive logic first. Inductive logic is more complicated and presupposes a grasp of deductive logic.

That shouldn’t be surprising: in a sense, deduction is just a special case of induction. A good inductive argument makes the conclusion likely to be true. If the premises guarantee that the conclusion is true, then that is maximally likely.

Now here's a slightly harder question. The American legal standard for a criminal conviction is “beyond a reasonable doubt”.