Skills of argument and logical inference

1. Meaning of argument

In logic, an argument is a set of statements in which some (the premises) are offered as reasons for another (the conclusion). It is not a quarrel; it is reasoned persuasion. Irving Copi defines an argument as “any group of propositions of which one is claimed to follow from the others, which are regarded as providing support or grounds for the truth of that one”. Indicator words help: since, because, for introduce premises; therefore, hence, so, it follows that introduce a conclusion.

In communication, argument is the skill of presenting a position with reasons and evidence so that the listener accepts it: in negotiation, in meetings, and above all in court.

2. Types of argument

(a) Deductive argument. The conclusion follows necessarily from the premises; if the premises are true and the form is valid, the conclusion must be true. The classic form is Aristotle’s syllogism:

• Major premise: Every contract by a minor is void.
• Minor premise: This agreement was made by a minor.
• Conclusion: This agreement is void.

Applying a statute to facts is deductive: the rule is the major premise, the facts the minor. An argument can be valid (correct form) but unsound if a premise is false.

(b) Inductive argument. Moves from particular instances to a general conclusion which is probable, not certain. “Sales rose in every month we advertised on radio; radio advertising increases our sales.” Its strength depends on the number and variety of instances. Market surveys, statistics and the drawing of a legal principle from a line of cases are inductive.

(c) Argument by analogy. Two things alike in known respects are probably alike in another. This is the basis of precedent: the facts of this case resemble those of a decided case, so the same rule applies. It is countered by distinguishing: showing a material difference.

(d) Abductive argument (inference to the best explanation). From an observed fact one reasons to its most likely explanation. A detective or a prosecutor relying on circumstantial evidence argues abductively: the chain of circumstances is best explained by the guilt of the accused.

(e) Causal argument. Asserts that one event caused another: the faulty wiring caused the fire; the breach caused the loss. It must exclude other causes.

(f) Argument from authority. Relies on an expert or a binding source: a Supreme Court judgment, a statute, an expert witness. In law it is strong when the authority is binding and relevant; it is a fallacy when the authority is not an expert on the point.

(g) Rhetorical (persuasive) argument. Aristotle’s three modes: ethos (credibility of the speaker), pathos (emotion), logos (logic). A good advocate uses all three, relying mainly on logos.

3. Toulmin’s model

Stephen Toulmin (The Uses of Argument, 1958) described practical arguments in six parts:

4. Logical inference

An inference is the mental process of drawing a conclusion from given facts or premises. Immediate inference draws a conclusion from a single proposition (“All directors are members” therefore “Some members are directors”). Mediate inference uses two or more premises, as in the syllogism. In evidence law, courts draw inferences from proved facts; under the Bharatiya Sakshya Adhiniyam, 2023 the court may presume the existence of facts it thinks likely to have happened, having regard to the common course of natural events, human conduct and business (s. 119, formerly s. 114 of the Evidence Act).

5. Common fallacies

• Ad hominem: attacking the person, not the argument.
• Straw man: misrepresenting the opponent’s argument to refute it.
• Hasty generalisation: induction from too few cases.
• False cause (post hoc ergo propter hoc): “after this, therefore because of this”.
• Begging the question: assuming the conclusion in the premise.
• False dilemma: presenting only two options when more exist.
• Appeal to emotion or to the crowd in place of reasons.
• Slippery slope: assuming one step must lead to an extreme result.

6. Skills of argument

1. know the facts and the law thoroughly; anticipate the opponent’s points;
2. state the issue first, then the proposition you want accepted;
3. arrange points from strongest to weakest, or in a logical sequence (IRAC: issue, rule, application, conclusion);
4. support every claim with evidence or authority;
5. concede what cannot be denied; it builds credibility;
6. listen to the other side and answer the actual argument;
7. be brief, courteous and calm; never argue with the judge;
8. use voice, pause and body language to stress key points;
9. close by restating the conclusion and the relief sought.

How this is examined

“What is argument? Explain different types of argument” (January 2026, 10; August 2024, 10). A short note on “skills of argument” or “logical inference” is possible. Answer with definition, premises and conclusion, then four or five types each with an example, and end with fallacies or the skills of argument.