Deductive reasoning has you starting with information or an idea that is called a premise.

Eventually, you come up with conclusions that are based on your original premise.

Sherlock Holmes, that detective guy from the books, uses deductive reasoning to solve mysteries.

Think of it this way:

(1) If this happens…

(2) and this happens…

(3) then you can come to this conclusion. If the premises are true, then your conclusion should also be true

Inductive Reasoning

Inductive reasoning works in the opposite direction. You start by having a number of observations. “I see that.” “That happens here.” “I believe that this will happen just like the others like the others because the circumstance is similar.”

It is a process in two parts. First, you start with specifics and come up with a theory. That’s deductive. When you apply that theory to new areas, it is inductive reasoning. You organize data into categories and say, “What do these have in common?”

There is a problem with inductive reasoning: your conclusions have more information than the facts you use. You start with dozens of observed examples, take an inductive leap, and assume millions of possible examples. If the conclusion is true, then new premises and assumptions are true.