The truth of a conclusion can be determined for that rule, based solely on the truth of the premise.

For example, "smokers are liable to die young”. Gordon is a smoker. He is therefore liable to die young.

This type of logic is used in mathematical and philosophy.

Deductive reasoning allows us to draw conclusions that must hold given a set of facts (premises).

A rule after a number of successful trials is taken to be a conclusion that follows from a precondition in terms of such a rule.

For example, “several smokers have died young”, therefore smokers are liable to die young.

Given a true conclusion and a rule, a valid premise is abducted to support the conclusion, though not uniquely.

For example, people who start to smoke early tend to die young.

A young man died. Therefore, he may have been a smoker.

This kind of reasoning is used to develop hypotheses, which in turn can be tested by further reasoning or data analyses.

Diagnostic and detective investigations adopt this type of reasoning.

Deductive logic builds a conclusion from accepted premises or general principles.
Inductive logic builds a conclusion from particular observations or examples.
Analogical logic borrows the logic from one situation and applies it to another.