Logic and Reasoning

Types of Reasonings

Deductive Reasoning

Inductive Reasoning

Abductive Reasoning

Logical Reasoning

Backward Induction

Critical Thinking

Analytical Thinking

Counterfactual Thinking


Deductive reasoning is also known as ‘top-down’ logic, where the reasoner begins with an accepted premise and seeks to prove another statement based on previously “known” information. Narrows the scope of that available information until his premise is the only logical conclusion remaining.

Using Deduction - A method used to reach a conclusion based on a guiding theory.

1 Understand deduction.

2 Build a theory.

3 Test your theory.

4 Sharpen your problem solving skills.

5 Think logically.

6 Expand your knowledge.

7 Relax.

Inductive reasoning, however, allows Sherlock to extrapolate from the information observed in order to arrive at conclusions about events that have not been observed. He goes on to gather information until he arrives at a conclusion — that still may be incorrect. And yet more information will come and come until he is quite sure he’s arrived at the right conclusion.

Eight steps: Observation

1 Know your subject.

2 Slow down and look outwards.

3 Try something new.

4 Improve your concentration by cutting out distractions.

5 Challenge yourself to a mental workout.

6 Test your observation by playing a memory game.

7 Record and consider your observations.

8 Stay inquisitive!

Inductive and deductive reasoning both strive to construct a valid argument. Therefore, inductive reasoning moves from specific instances into a generalized conclusion, while deductive reasoning moves from generalized principles that are known to be true to a true and specific conclusion.

Abductive reasoning is useful for forming hypotheses to be tested. Abductive reasoning is often used by doctors who make a diagnosis based on test results and by jurors who make decisions based on the evidence presented to them.

Logical reasoning. Two kinds of logical reasoning can be distinguished in addition to formal deduction: induction and abduction. Given a precondition or premise, a conclusion or logical consequence and a rule or material conditional that implies the conclusion given the precondition, one can explain the following.