Flaws in Reasoning

Flaws are defects or fallacies in somebody's logic. In other words, flaws are questionable or wrong assumptions in a writer's/ a speaker's  line of reasoning. 

When a writer/ a speaker presents his/ her argument, he/ she makes a claim, and gives some premise(s) or logic to support his/ her claim. Sometimes, a writer/ a speaker misinterprets the available premise(s)/ evidence(s), or attaches personal bias to the available premise(s)/ evidence(s). This makes his reasoning flawed or erroneous.

In various competitive examinations, there are questions of critical reasoning in which candidates are expected to expose the flaws in an author's reasoning. Even in day-to-day interaction with people, one can realize that people at times make flawed argument. Therefore, it is of paramount importance to detect the flaws in reasoning, and to understand the nature of flaws.

Types of Flaws:

These are some of the flaws that we see in arguments.

1. Generalisation: Here, an author draws a sweeping statement or a very broad claim on the basis of the limited data that he/ she has.

2. Confusion between coincidence and causation: Here, an author considers a coincidence to be causation. Coincidence is something that happens by chance, whereas causation means logical cause-effect relation.

3. Invalid assumption: Here, an author relates two things which have no connection.

4. Unrepresentative/ irrelevant data: Here, data presented by an author is either incomplete or irrelevant and from this data, the author tries to make convincing argument. But a careful thinking will enable us to understand the irrelevance.

5. 'Only this' fallacy: Here, an author offers only a single explanation for something that has happened. or he/ she suggests a single course of action for a complex problem, assuming that one change/ one action is enough to sort out the problem.

6. Assuming that time is constant: Here, an author considers that what was true earlier is true even now, assuming that time has not changed.

7. Weak analogy: Here, an author erroneously compares two dissimilar individuals or things or situations.