Critical Thinking #7

English: inductive and deductive reasoning (Photo credit: Wikipedia)

We discussed about the types of logic in the seventh class of the course. Our teacher said that there are two types of logic– inductive logic and deductive logic.

Deductive logic is always valid. It can either be sound or unsound.

Example for a valid but unsound deductive argument :

R1 : All birds can fly.R2 : Penguin is a bird.C : Peguins can fly.

Example for valid and sound deductive logic:

Nothing that is cheap is good.Therefore, nothing that is good is cheap.

Maths is full of deductive logic. In deductive logic one can be always sure that there is 100% validity.

Inductive logic is stating examples and then generalizing it.

Example for inductive logic:

R1: Satellite picture show a cold front moving eastwards across the Canadian coastline 

R2: It moves with a trough of low pressure along its leading edge. 

R3: It will meet up with a large mass of rotaing wind moving across the Atlantic to scooping down from the easterly-winds sweeping down from the artic.

C: Consequently violent stroms can be expected to develop in the north Atlantic in next 24 hours.

Here, we are stating examples and then concluding. We do not know if its 100% valid in inductive logic, though it may be sound.

We learnt the difference between the two.