A-level Critical Thinking/Types of reasoning

  • Simple reasoning – There is a conclusion that is supported by a reason.
  • side by side reasoning – Two reasons independent of each other support a conclusion.
  • Joint reasoning – Two reasons from which one conclusion can be drawn. It would not be possible to draw a conclusion from one of the reasons on its own.
  • Chain reasoning – Reasoning linked together.
  • Joint reasons: Reasons which have been used together to support a conclusion.
  • Assumption: An Assumption is an unstated reason
  • Principal: A principal is a general statement about how something should be. There are moral, legal and ethical principals. Principals are inflexible and cannot be bend to fit particular situations.
  • Counter argument: A counter argument is an argument that opposes another argument. Counter arguments can be included in an argument in order to dismiss that argument .
  • Counter claims: Counter claims or counter assertions are claims that are dismissed in an argument. The claims to not agree with the main conclusion.
  • A counter-example is an example that challenges the truth of a claim. Counter-examples challenge generalizations.


  • Hypothetical reasoning - Something will happen on the condition that something else happens .
  • Value judgements – A judgement based upon a value (e.g. murder is wrong). People have conflicting values and values change over time.
  • Definitions – Definitions are precise meanings of a word or phrase. Definitions can be argued other e.g. the definition of rape.


  • Causal explanations – Cause and effect (Smoking causes cancer).
  • A common cause – A correlation between two things is caused by a third factor.

A correlation between two things may be caused by chance .


  • Direction of causation – Does A cause B or does B cause A.

Some things have multi-causal explanations – explanations which show that there are more than one causes causing an effect.


An analogy is a comparison between two things which are seen to be similar .


Criteria to evaluate an argument by analogy 1. Number of instances 2. Number of similarities 3. Strength of conclusion 4. Relevance 5. Number of differences

Extreme analogies should be avoided as they can weaken an argument