Deductive reasoning is the process of reasoning from the general to the specific. Deductive reasoning is supported by deductive logic, for example:
From general propositions:
- All ravens are black birds.
- For every action, there is an equal and opposite reaction
To specific propositions such as:
- This bird is a raven, therefore it is black.
- This billiard ball will move when struck with a cue.
In contrast to inductive reasoning
, the conclusions of deductive reasoning are as valid as the initial assumption.
Deductive reasoning was first described by the ancient Greek philosophers such as Aristotle.