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The craft of a lawyer: how to persuade a Judge. Part 2 Legal Arguments: Use of Formal Logic

Logic and Structure of Legal Argument

When a lawyer hears a case from a prospective client for the first time, in most cases he forms an opinion instantly about whether the claim of the litigant is justified. It is also possible that two lawyers, hearing the same client, will form two contrary opinions, so the opinion formed is dependent of many subjective factors. The challenge in advocacy lies in presenting the claim of the client to a judge so that he too will feel that the claim of the client is justified. The immediate arguments that come to the mind are generally emotive; expressions of the lawyers own or the clients feelings of the injustice being meted to the aggrieved person. Most often a Judge may find such arguments a waste of courts time. A Judge would expect him to show the provision of a statute or a past decision of a court as grounds for staking the claim made in the petition which the lawyer would certainly do. The Judge would want him to demonstrate how such provision or decision helps his case. The process through which a lawyer makes that demonstration, to show that a particular statute or case law does apply to his case, is through legal reasoning, which uses a form of logic termed as “syllogism”

The issue of how a lawyer should build his argument goes to the root of a bigger question; how does a Judge decide a case and lay down a legal rule? For Natural Law Jurists the only question worth asking in Jurisprudence is how laws are laid either through legislative process or judicial. It is said that a Judge never makes a law, which is the work of the legislature, but he “discovers” the law for each dispute and he applies it to pass a decree. The discovered law may be taken from a common law or it could be a law laid down by the legislature, or interpretations thereof capsuled in case laws. The so called discovery is a process of locating the relevant law and interpreting it to reach a meaning that can then be employed to decide the dispute which is to be adjudicated. The process is lucidly explained by Aharon Barak when he describes a Judges journey through a process of decision making as discovery of the ‘purpose’ of laws. He divides purpose in two parts: subjective purpose, which is one where the adjudicator tries to discover the meaning of the author of that statute and the objective purpose which are the fundamental values of a legal system that guide making of laws. A judge sets himself discovering the law by determining the purpose of laid down laws, first by subjective purpose methods and then by looking for the objective purpose, if ambiguities do not get resolved by subjective method, and finally he deductively arrives at a decree which would resolve the dispute before him.

Interpretation is not the subject of this article. It is the core learning of legal profession and would not come in the scope of a paper on craftsmanship which relates to the more mechanical aspects of a lawyer’s profession. Once a lawyer adopts an interpretation of law and uses it to build his claim for the client, the lawyers work is then to demonstrate that the discovery, which may have convinced him, is applicable to the facts of the case by the rules of syllogism. The idea put forth here may sound esoteric but it would appeal to common sense if it is explained with an example drawn from physical sciences.

Dr. Henig Brand of the late seventeenth century, living in Hamburg Germany, was convinced, like most brilliant people of the times, that Philosopher’s Stone could be discovered which will turn ordinary metal to gold or silver. He spent the fortunes of both his two wives on his private laboratory experiments. His first wife was rich and he married another rich lady after becoming a widower. Using human urine he obtained a hitherto unknown substance, a black mass which burned of its own in air. The distillate was magical and produced light and Dr Brand was convinced that he had found a hitherto unknown substance and called it Phosphorous. If he had then staked a claim of having found a Philosophers Stone, many would have believed him because no new substance had been discovered till then from the ancient times. However, in such an eventuality, all the learned persons who were engaged in the same pursuit would have challenged him with a syllogism-driven question. ‘Did your stone turn any known metal in to gold or silver?’ It so happened that Dr Brand did not want to make any claim because he was more interested in obtaining gold from his find and he kept the discovery a secret till it was conclusively proved to him that the new find had no propensity to make gold. But suppose he had staked a claim of having found a Philosopher’s Stone, then his challenger would have rebutted him with the following syllogism:-

Philosophers Stone always turns cheap metal to gold (Major Premise)

Dr Brand’s stone did not turn any metal to gold (Minor Premise)

Dr Brands stone is not a Philosopher’s Stone

In the physical sciences it is hardly necessary to put a statement in such a syllogistic form. It is well understood that experimental proofs must be annexed to each claim of discovery. In the practice of law, however, in course of court argumentation it often becomes necessary to challenge adversary claims in a formal syllogistic form. Lawyers, due to inexperience, or due to pressure to defend their client, often tend to make syllogistically unsound claims in their grounds of appeal or rebuttal. In making discoveries of law to suit a client’ claim, it may happen, a lawyer may make a finding which does not help him but it may still be useful, like the non-metal found by Dr Brand, phosphorus. Discoveries made by a lawyer which is recorded by the Bench in the judgement may be rejected as syllogistically irrelevant to that case, but may become useful for deciding another unrelated dispute.

Judgements are permeated with syllogistic reasoning though neither is this word used nor a formal diagrammatic presentation made of the logic behind the decision. All decisions of courts settle disputes between two litigating parties and the adjudicators not only decide the case but follow it up by writing a judgment where they give reasons for coming to that decision. A judgment seeks to show that given the prevalent law, which is stated in the judgment, which in field of syllogism is called a major premise, when applied to the set of facts in the suit, of which the judge provides a description, which is a minor premise, syllogistic logic forces him to opt for the decree that he has made.

In this paper we analyse the form of logic, ‘syllogism’ that holds the structure of the judgement and ‘inductive logic’ that is used to test certain kinds of premises that are inferences from empirical data. We use epistemological works to understand these forms of logic. The one name that shines prominently in this field of knowledge is the Greek philosopher Aristotle who contributed significantly to epistemology. He had explained the concept of syllogism in deductive logic which has been read through the centuries. Much of what the world understands of these concepts is owed to him. Similarly inductive logic is used in everyday life and theorising is generally based on such logic. A good understanding of formal logic helps lawyers detect the strength of arguments and demonstrate the superiority of their own. The objective is to show that the adversarial arguments are based on logical fallacy.

Fundamentals of Deductive and inductive arguments

The value of a deductive logic is adjudged in terms of its validity. The inference is either true or false, it can never be both, or possibly false or likely to be true. That conclusion has a certainty that is common only in mathematical exercises. We are concerned with syllogism form of deductive logic, whose standard form is as below:-

Premise 1: A is B

Premise 1: C is B

Inference: C is A

A, B and C are categories and they are of use only when we insert actual values in them. One may therefore create a syllogism as below:-

Premise A: All persons born in Delhi are natives of India

Premise B: Mr X was not born in Delhi.


Conclusion: Mr X is not a native of India.

This syllogism has used three categories, namely:-

‘All persons born in Delhi’ > category A

‘Natives of India’ > category B

‘Mr X’ > category C.

In the exercise of deductive logic one studies if the logic is valid. The above argument is invalid. It is possible to be born in some other place than Delhi and still be an Indian. Deductive argument is good only if it valid. This deductive logic is invalid and therefore useless. The fact that it is not even true that persons born in Delhi would become Indians as for instance a child born to a diplomat living in India is not relevant for adjudging whether the logic is valid. That fact is relevant to test the soundness of the premises not the validity of the argument.

There can be another illustration such as this: -

Premise A: All persons born in State of New Jersey are Indians

Premise B: Mr X was born in New Jersey.


Conclusion: Mr X is an Indian.

This deductive argument is perfectly valid as the logical relationship between two premises has been correctly maintained. The fact that it is based on one false premise which says that the State of New Jersey, located in USA has only Indians in its population, does not affect the validity of the logic. Though valid, the syllogism is rendered useless as one of its premises is unsound. Only such deductive logic that are both valid and sound are good and useful.

The other form of logic employed in legal practice is inductive logic which is about possibilities or probabilities. This form is applied extensively in statistics. An example of this form is the conversation below:

Question- Did the sun shine in the sky yesterday at 6am though all were sleeping

Answer – Yes, it did.

Question - What are the premises for this answer?

Answer - Premise 1- The sun was shining at 6 am day before yesterday

Premise 2- The sun did shine at 6 am before that.

Premise 3- The sun has shined at 6 am ever since the present season set in.

Premise 4- The sun always shines in the morning sky in this season.

Premise 5- No one noticed any cloud in the sky yesterday.


Conclusion: The sun did shine yesterday morning.

In this argument one would find that it is not outside the realm of the possible that the sun did hide behind clouds smoke or even due to a freak astronomical event and for that reason the sun was not visible at 6 am yesterday. Hence this argument is invalid as a deductive argument, the premises do not bear the inference. The argument however is good under inductive logic because it provides good reasons for any person to conclude that there was sun shine yesterday even if no was awake to see it. A deductive logic is all or nothing; either the argument passes the muster of being valid or it deserves to be rejected entirety because it is invalid. The strength of an inductive argument is a matter of degree; some arguments may be good but weaker than other arguments. The chances that sun did rise in a season in which clouds do not show in sky and no freak event was reported is enough ground to conclude inductively that sun did shine yesterday.

In inductive arguments what an evaluator tries to judge is whether the argument is strong enough for the purpose it will be used. It is possible that an argument which is adjudged strong may later be considered weak when new information is received. Thus such arguments are defeasible whereas deductive arguments are indefeasible and no matter what information is received subsequent to drawing of inference, the deductive arguments validity will remain unchanged making it indefeasible.

Syllogism, the core of any judicial decision, is prepared using three categories only. It contains two premises and one conclusion where the word ‘premise’ is meant to refer to a statement which provides reasons for the conclusion.

The word category is used to mean a class of group of different situations, things, events or persons which have common characteristics that makes them capable of being classified in sets and sub sets depending on the manner in which they are differentiated, and each such set or sub-set is a category. ‘This case’ part of the conclusion could be a particular item, thing, or event, or a cause of action, and the ‘category B’ is a broader category which is well recognised by persons engaged in argumentation and could be a legal rule.

Major premise of a syllogism concerns category B mentioned whereas the Minor Premise deals with portion X mentioned in the conclusion. In any litigation, the part X is what the cause of action is about, and B is the law which should govern that cause. Legal syllogism can be expressed in two ways.

Assuming that ‘A’ & ‘B’ are two categories, the first Syllogism reads as follows:

Major Premise: A is B.

Minor Premise: This particular case (X) is A.

Inference: This case (X) is B.

A Syllogism can also be expressed in its negative variant, as:

Major Premise: Only A is B.

Minor Premise: This particular case is not A.

Inference: This case is not B.

In legal Syllogism, the Major Premise is a statement of legal rule that will govern a set of facts. The Major Premise is generally a part of the statutory framework in a taxation case. However, it could be rule laid down by the Apex Court or by any Court of Law. The Minor Premise is narration of facts which invite the application of that legal rule. Human reason dictates that if there is no dispute about the Major Premise or the Minor Premise, there can be no dispute over the inference.

A standard Syllogism in a tax adjudication would run as follows:

Major Premise: Under the Central Excise Act, manufactured goods have to discharge CENVAT duty at the time of removal of goods.

Minor Premise: M/s. ABC has been removing manufactured goods for the past 5 years without payment of duty.

Inference: M/s. ABC is liable to pay duty for all the goods cleared in the period.

A counter argument can be made for M/s ABC to the bench in its negative form.

Major Premise: Only goods that have been manufactured are required to pay duty at the time of their removal from the factory under the Central Excise Act.

Minor Premise: Goods that were taken out from the premise of M/s. ABC had been purchased from market for trading.

Influence: Goods used for trading are beyond the scope of the charging section of Central Excise Act.

Another possible argument from the other side could be as follows:

Major Premise: Only goods that have been manufactured and removed from a factory are required to pay duty at the time of their removal under the Central Excise Act.

Minor Premise: There is no evidence that goods were manufactured within the factory premise and hence no goods were manufactured or removed.

Inference: No duty is payable by M/s. ABC.

In the above case of evasion of central excise duty, both the department and the assessee have used syllogism; department has used positive syllogism to demand duty whereas the assessee has used its negative variant to build their reply. In both the arguments the Major Premises are above doubt and cannot be doubted. It is the soundness of the minor premises that would have to be tested by the adjudicator in the course of hearing of the case.

There is no rule that the respondent’s argument need to be couched in the negative form of syllogism only. A case of service tax could proceed in a manner in which the department raises demand through the following argument:

Major Premise: Services which were provided and consumed in the Indian taxing territory is liable to pay service tax except for services mentioned in the negative list.

Minor Premise: M/s. ABC provided services which were consumed in India.

Inference: M/s. ABC is liable to pay service tax.

The counter argument that can be raised by opposite side could be something as follows:

Major Premise: Only services that have been paid from India for services consumed in India is liable to discharge service tax.

Minor Premise: The payment for the services to M/s. ABC was made by a company M/s. XYZ, which is located abroad.

Inference: No service tax is payable.

This argument can also be presented in a positive syllogism, which would read as follows:

Major Premise: Services which are exported out of India are not liable to service tax.

Minor Premise: M/s. ABC has provided service to M/s. XYZ, a company located abroad and has received payment in foreign exchange from abroad.

Inference: Services provided by M/s. ABC are exempt from tax.

This case both the sides are likely to make use of syllogism of both negative and positive kind. The course of hearing would resemble the voyage of a small vessel in choppy waters where it gets rocked from one side to the other by force of successive syllogisms. Each syllogism of the opponent would need to be rebutted by one side and then that side would need to place for the court’s examination another syllogism which supports their case, which would have to stand its ground in the arterial attack that the court would permit the opponent to launch on that argument. It is this circular course of argumentation which gives a hearing its very distinctive character.

In this case on taxability of a service, no allegation has been made by anyone that either side has made a suppression of facts or misstated the facts in the records of the case. The main test in the case lies in examination of the Major Premises and a responsibility is cast on the side using a syllogism to read out the specific provision in the statute or subordinate legislation, or decisions of the superior courts that supports their Major Premises. Knowledge and understanding of the service tax law, in its statutory text as well as Apex Court’s decisions and the ability to use that knowledge in verbal argument would matter the most in the outcome of the hearing.

Citing Precedent Case Law and use of Inductive Logic

In common law countries, courts will take an issue as settled in law if a superior court has already ruled over it and delivered a judgment. This principle gets statutory firmness in India by Article 141 of the Indian Constitution which says that the law declared by the Supreme Court shall be binding on all the courts within its territory. A precedent of the higher court is said to be on all fours only if the facts are same, the persons affected by the judgement are identically placed and the statutory provision interpreted is the same. If the major and minor premises of a precedent are the same as the lis (the dispute which is being argued) nothing remains to be done by the counsel except to admit that the said court is bound by it and hence they have no option but to follow the precedent rule. However it is rare that the major minor premises will be identical in all respects and the precedent has been offered to the court as being analogous to the lis. A major premise is about the rule of law involved in the precedent and minor premise would be about the factual matrix. Most of the real life situations arise on the minor premise as in the case below.

Major Premise: Segregated schools are unconstitutional

Minor Premise: A language college by insisting on ethnic criterion in class formation segregate students.


Segregated classes are unconstitutional

An example could be the decision that segregated public schools are unconstitutional. By analogy it could be argued that segregated colleges are unconstitutional or that segregated medical schools are unconstitutional. If an argument such as this is raised it would be contested on the strength of the analogy. The opposites would get engaged in listing out similarities or dissimilarities but it is for the adjudicator to evaluate how strongly is the case law offered analogous to the lis. In the above example the dissimilarities with school education is so evident that the inference could hardly be considered sound. The recognised standards of strength applied to a lis on segregated colleges would read something as follows:-

  1. Are the similarities on the important aspects of the case?

(- school college medical school are all about education, which is the important thing about a school. Language school is different from other schools because it makes sense from educational purpose to group persons with similar language skills together.)

  1. Are there adequate number of similarities?

(- besides being about education, they all receive public funds and so on)

  1. Are there fewer dissimilarities than similarities?

(- the only dissimilarity is that school is about basic education which is guaranteed to all under law)

  1. Are the objects which are similar diverse?

(- fairly diverse in this case as schools and colleges would have many commonality in terms of activity, structure and management)

  1. Is the conclusion’s strength commensurate with the quality of the analogy?

(- a fairly strong inference would do in this case but not one that admits of no doubts).

Classifying an opponent’s syllogism as a Fallacy

The formal way to rebut a syllogism put forth by the opponent in legal pleadings, is to demonstrate the form of the logic as a fallacy. If it can proved that an argument’s form is a fallacy, nothing else remains of the argument in the eyes of a judge and the evaluator. A short course in formal fallacies is essential in the development of a counsel or in an adjudicator’s education. A good source for formal logic is the Wikipedia. Since we are principally concerned with Syllogism, the five fallacies in relation to Syllogism given in Wikipedia has been used for this section.

1. Affirmative conclusion from a negative premise (illicit negative) is a formal fallacy in syllogism that is committed when a categorical syllogism has a positive conclusion, but one or two negative premises.

No dogs can fly, and

no fish are dogs,

therefore all fish can fly.

The only thing that can be properly inferred from these premises is that some things that are not fish and which cannot fly, provided that dogs exist.

2. The fallacy of exclusive premises is a syllogistic fallacy committed in a categorical syllogism that is invalid because both of its premises are negative.

Proposition: No mammals are fish.

Proposition: Some fish are not whales.

Proposition: Therefore, some whales are not mammals.

3. The fallacy of four terms is the formal fallacy that occurs when a syllogism has four (or more) terms rather than the requisite three. This form of argument is thus invalid.

Categorical syllogisms always have three terms:

Major premise: All fish have fins.

Minor premise: All goldfish are fish.

Conclusion: All goldfish have fins.

Here, the three terms are: "goldfish", "fish", and "fins". Using four terms invalidates the syllogism as in the following example:-

Major premise: All fish have fins.

Minor premise: All goldfish are fish.

Conclusion: All humans have fins.

The premises do not connect "humans" with "fins", so the reasoning is invalid. Notice that there are four terms: "fish", "fins", "goldfish" and "humans". Two premises are not enough to connect four different terms, since in order to establish connection, there must be one term common to both premises.

In everyday reasoning, the fallacy of four terms occurs most frequently by equivocation (the misleading use of a term with more than one meaning or sense) which means using the same word or phrase but with a different meaning each time, creating a fourth term even though only three distinct words are used. Example is such a fallacy would be as follows:-

Major premise: Nothing is better than eternal happiness.

Minor premise: A ham sandwich is better than nothing.

Conclusion: A ham sandwich is better than eternal happiness.

The word "nothing" in the example above has two meanings, as presented: "nothing is better" means the thing being named has the highest value possible; "better than nothing" only means that the thing being described has some value. Therefore, "nothing" acts as two different words in this example, thus creating the fallacy of four terms.

Another example of equivocation, a trickier one is as follows:-

Major premise: The pen touches the paper.

Minor premise: The hand touches the pen.

Conclusion: The hand touches the paper.

This is clearer if one uses "is touching" instead of "touches". It then becomes clear that "touching the pen" is not the same as "the pen", thus creating four terms: "the hand", "touching the pen", "the pen", "touching the paper". A correct form of this statement would be:

Major premise: All that touches the pen, touches the paper.

Minor premise: The hand touches the pen.

Conclusion: The hand touches the paper.

Now the term "the pen" has been eliminated, leaving three terms. This argument is now valid but unsound because the major premise is clearly untrue. The fallacy of four terms also applies to syllogisms that contain five or six terms

Note: Sometimes a syllogism that is apparently fallacious because it is stated with more than three terms can be translated into an equivalent, valid three term syllogism. For example:

Major premise: No humans are immortal.

Minor premise: All Greeks are people.

Conclusion: All Greeks are mortal.

This syllogism apparently has five terms: "humans", "people", "immortal", "mortal", and "Greeks". However it can be rewritten as a standard form of syllogism by first substituting the synonymous term "humans" for "people" and then by reducing the term "immortal" in the first premise to read “All humans are mortals”. This is therefore a valid syllogism.

4. Illicit major is a formal fallacy committed in a categorical syllogism that is invalid because its major term is undistributed in the major premise but distributed in the conclusion. Distribution of term is a concept of logic: if all members of the term's category is affected by the proposition, that category is distributed; otherwise it is undistributed.

Distribution of a technical term is a concept of logic which states that if all members of the term's category are affected by the proposition, that category is distributed;

Undistributed: If the reference is only to part of the class, then the class is said to be undistributed. A term is undistributed when it refers to less than all the members of its class (not fully occupied).

This fallacy has the following argument form:

All A are B

No C are A

Therefore, no C are B

An example of such a fallacy as would be met in real life situation is as follows:-

Major Premise: All dogs are mammals

Minor Premise: No cats are dogs

Conclusion: Therefore, no cats are mammals

All nationals of A are patriot

No national of B is national of A

Therefore no national of B is a patriot

In this argument, the major term is "patriot". This is distributed in the conclusion (the last statement) because we are making a claim about a property of all mammals: that they are not cats. However, it is not distributed in the major premise (the first statement) where we are only talking about a property of some mammals: Only some mammals are dogs.

The error is in assuming that the converse of the first statement (that all mammals are dogs) is also true.

However, an argument in the following form differs from the above, and is valid:

All A are B

No B are C

Therefore, no C are A

There is a rule of logic that all terms undistributed in the conclusion must be undistributed in the premises. In short you can compare apples with oranges.

5. Illicit minor is a formal fallacy committed in a categorical syllogism that is invalid because its minor term is undistributed in the minor premise but distributed in the conclusion.

Note: Distribution of technical term is a concept of logic which states that if all members of the term's category are affected by the proposition, that category is distributed; otherwise it is undistributed.

This fallacy has the following argument form:

All A are B.

All A are C.

Therefore, all C are B.


All cats are felines.

All cats are mammals.

Therefore, all mammals are felines.

The minor term here is mammal, which is not distributed in the minor premise "All cats are mammals," because this premise is only defining a property of possibly some mammals (i.e., that they're cats.) However, in the conclusion "All mammals are felines," mammal is distributed (it is talking about all mammals being felines). It is shown to be false by any mammal that is not a feline; for example, a dog.

In real conversation the problem may be encountered in the following manner:-

Pie is good.

Pie is unhealthy.

Thus, all good things are unhealthy.

6. Negative conclusion from affirmative premises is a syllogistic fallacy committed when a categorical syllogism has a negative conclusion yet both premises are affirmative. The inability of affirmative premises to reach a negative conclusion is usually cited as one of the basic rules of constructing a valid categorical syllogism.

Statements in syllogisms can be identified as the following forms:

a: All A is B. (affirmative)

e: No A is B. (negative)

i: Some A is B. (affirmative)

o: Some A is not B. (negative)

The rule states that a syllogism in which both premises are of form a or i (affirmative) cannot reach a conclusion of form e or o (negative). Exactly one of the premises must be negative to construct a valid syllogism with a negative conclusion. (A syllogism with two negative premises commits the related fallacy of exclusive premises.)

Example (invalid aae form):

Premise: All colonels are officers.

Premise: All officers are soldiers.

Conclusion: Therefore, no colonels are soldiers.

The aao-4 form is perhaps more subtle as it follows many of the rules governing valid syllogisms, except it reaches a negative conclusion from affirmative premises.

Invalid aao-4 form:

All A is B.

All B is C.

Therefore, some C is not A.

This is valid only if A is a proper subset of B and/or B is a proper subset of C. However, this argument reaches a faulty conclusion if A, B, and C are equivalent.[1][2] In the case that A = B = C, the conclusion of the following simple aaa-1 syllogism would contradict the aao-4 argument above:

All B is A.

All C is B.

Therefore, all C is A.

NOTE- The concept of negative conclusions from positive premises is simple and not difficult to understand. The concept of a.e.i.o is technical. It is important to know these terms for continuing study of logic as they are frequently used.

7. The fallacy of the undistributed middle is a formal fallacy that is committed when the middle term in a categorical syllogism is not distributed in either the minor premise or the major premise. It is thus a syllogistic fallacy and most widely used by logicians to refute an opponent’s arguments.

Note: Distribution of technical term is a concept of logic which states that if all members of the term's category are affected by the proposition, that category is distributed; otherwise it is undistributed.

Example of this would be as follows:-

All students carry backpacks.

My grandfather carries a backpack.

Therefore, my grandfather is a student.

The middle term is the one that appears in both premises — in this case, it is the class of backpack carriers. It is undistributed because neither of its uses applies to all backpack carriers. Therefore it can't be used to connect students and my grandfather — both of them could be separate and unconnected divisions of the class of backpack carriers. Note below how "carries a backpack" is truly undistributed:

‘grand father is someone who carries a backpack; student is someone who carries a backpack’

However, if the latter two statements were switched, the syllogism would be valid:

All students carry backpacks.

My grandfather is a student.

Therefore, my grandfather carries a backpack.

In this case, the middle term is the class of students, and the first use clearly refers to 'all students'. It is therefore distributed across the whole of its class, and so can be used to connect the other two terms (backpack carriers, and my grandfather). Again, note below that "student" is distributed:

‘grandfather is a student and thus carries a backpack’

Conceptual Slippery Slope Fallacy of inductive logic.

Though a smart counsel must be quick to detect a legal fallacy, however the occasion for it may not arise as the bench is likely to detect it as well and dismiss it as a fallacious argument. An AR can save the time of the court by exposing fallacies and those enhance their own credibility. It is however use of inductive reasoning for discovering legal precedents that leads to quoting of inapplicable precedents and they are more difficult to rebut as they provide the bench with facility to decide a difficult matter.

Counsels in CESTAT often use weak inductive reasoning for trying to demonstrate that in a similar matter the court has held in their favour though the points of similarity are very tenuous. They would argue that the said decision should be followed by the CESTAT bench in keeping with the principle of legal precedents. It is the ability to counter such use of weak precedents that stand on the slippery slope of analogy which is mark of a successful counsel, especially in hearing for stay of recovery in which the department does not get time to respond and there is no system of filing written replies after the hearing and before the order is dictated.

The formal definition of a slippery slope fallacy is that it is one which exploits the vagueness of a category to argue that there is no significant difference between the things that belong to that category and things that do not. A judicial slippery slope argument is one that exploits the vagueness of a category to argue that it is unfair to treat cases that fall in to a category differently from cases that do not fall in to that category. An example is as follows:-

A 9 month old human foetus has a right to live

A difference of 1 minute of prenatal development is not a significant difference


It is not fair to deny a fertilised human egg the right to live

The inference is not supported by the two premises due to the slippery slope on which it stands. The difference between a 9-month foetus and fertilised egg is not of 1 minute or even few minutes. It is a huge difference and therefore it is significant. The insignificance of 1 minute difference therefore lends no support to the inference.

Greater the number of judges to hear a matter, higher the precedent value of their decision.

A single member bench to hear a difference of opinion implies decision by 3 judges in a case.

Reference to a three member bench sitting together means decision by 3 judges (such bench is also made to hear a difference of opinion of 2 members)


The value of decision given by a single judge hearing a case after 2 judges have disagreed is the same as that of decision by a three member bench sitting together and deciding the same case.

The above argument is a fallacy because in order to reach the inference is has slipped down a slippery slope in a manner that can be illustrated by a more recognisable parallel illustration as below:


A person who is 1 meter in height is short

A difference in 1 millimetre is not a significant difference

A person who is 2 meters in height is tall


There is no significant difference between being short and tall

(The argument assumes that 1 meter is after all a collection of several 1 millimetres and thus it has fallen down the slippery slope.)

Just as the conclusion regarding difference between tall and short is not supported by the three propositions that precede it so also the conclusion that the value of a decision by 3 members is same as that of a single member is not supported by propositions that precede. Even if a numerical count is taken the total number of judges that decide in the second case becomes 5 hence the argument is mounted on a slippery slope of count. It is a different matter that the argument misses the qualitative difference in decisions taken by single member and bench of 3 members.

Slippery slope fallacy does not make an argument false because even if the comparability of the situations are tenuous, the inference may be true on its own merit. Such inferences are not supported by the premises hence there is reason to muster other arguments for supporting or opposing the argument.

Techniques of Refuting an Argument.

  1. Counter Example:

The formal way to refute an argument is by demonstrating that the argument is fallacious in any manner recognised in epistemology. It is however not so common for any counsel to show exactly which fallacy has been committed by the opponent. If an argument does not easily fit in to any of the known forms of fallacy, it can still be refuted by putting up an example that runs counter to any of the premises and when one of the premises is shown to be false, the conclusion drawn from it automatically becomes unsound and useless.

In legal syllogism, the minor premise is often made of a generalisation from a set of established facts. One of the most tested methods to show that the generalisation is unsound is to use an example that runs counter to the generalisation. Counter example can be used not only on minor premise but in any part of the argument including the conclusion.

You should always treat others the same way that you will like to be treated

I would not like anyone to change my diapers.


I should not change the baby’s diapers.

The first premise is a wrong generalisation because what is applicable to adults is not applicable to children. Children cannot be treated as adults. This premise is similar to another generalisation that ‘one should usually treat others the same way that you will like to be treated. The two statements are different which is demonstrable by the example of children not being adults.

If it is wrong for all of us to perform a particular action, then it wrong for any of us to perform that action.

It is wrong for all of us to take the last piece of bread on the table


It is wrong for any of us to take the last piece of bread on the table.

The conclusion can be shown as wrong by a counterexample. If few persons sit to eat and they eat up all the bread except the last piece. Is it right to let that piece go waste? Since it is not, someone has to eat it and hence this example demonstrates that the conclusion is wrong.

  1. Parallel reasoning: -

An argument can also be refuted by finding another argument that has exactly the same form as the first argument but it can clearly recognised as a fallacy. It is then argued that since the second argument is a fallacy, the original argument which has the same form must also be a fallacy. This refutation is not as convincing as the formal method, yet this is commonly used in conversational act, a genre to which legal reasoning belongs.

If I had a higher salary I could buy a bigger house


Therefore if every ne had a higher salary, everyone could buy a bigger house.

Parallel argument

If one person stands up in a football match, then she will get a better view


If all persons stand up in a football match, then all will get a better view

The second argument is obviously fallacious as in a football match if all spectators rise from their seats they will block the view of those who are standing to watch the game as well.

Most people who start business ignore statistics of failure

Most people who ignore statistics of failure are stupid


Therefore: Most people who start businesses are stupid

This argument is fallacious because we know that clever people who do understand that starting a business is likely to lead to failure do so with full knowledge of the risks involved in the undertaking entrepreneurial venture. The fallacy is easily revealed in this parallel reasoning as below:-

Most of my friends are organisms

Most of organisms are microscopic


Most of my friends are microscopic

In the parallel reason, human beings make friendship with other human beings who are all organisms named Homo sapiens. It is a biological fact that there are far many more microorganisms living in this planet than mammals. But human beings are not microorganisms.

This kind of parallel reasoning can be used in arguments before the benches. Suppose in a case on service tax, it is argued that if the payment is made by A for service of money transfer, then even if the person ‘B’ receiving the cash from money transfer operation, is located in India, it will be person ‘A’ who pays for it who should be considered to have used or consumed the service of money transfer. A parallel argument could be found in coaching class services. If the parent ‘A’ located abroad pays for his son to attend coaching classes in Delhi, can that parent A be considered to have used the service? The thrust of this argument is the obvious inference that a person who consumes coaching class service must have gained in knowledge skill in taking entrance exams or colleges or services. There can be no doubt that the parent would not be thought as user of the service of the coaching class service so it follows that in the parallel argument too person B must be considered as the user of the service.

Refutation by parallel reasoning is not always effective. The argument that needs to be refuted is as follows:-

If guns are outlawed, only outlaws will have guns

It would be bad if only outlaws had guns


Therefore guns should not be outlawed

Refutation by the following parallel argument appears to be weak and unsustainable:-

If gum is outlawed, only outlaws will have gum

It would be bad if only outlaws had gum


Therefore gum should not be outlawed

The later argument about gums is not really fallacious hence the parallel does not help in refuting the first argument about guns. If gum is a bad thing but unlike a gun, does no harm to others besides their user, it may not be so bad if outlaws only had gum.

  1. Demonstrating an argument as Reductio Ad Absurdum.

Reductio Ad Absurdum is an argument that a particular hypothesis is false because it implies an absurdity. Reduction to the impossible, is found repeatedly in Aristotle’s Prior Analytics. In its most general sense, reductio ad absurdum – reductio for short – is a process of refutation on grounds that absurd – and patently untenable consequences would ensue from accepting the item at issue. This takes three principal forms namely:

  1. a self-contradiction (ad absurdum)

  2. a falsehood (ad falsum or even ad impossible)

  3. an implausibility or anomaly (ad ridiculum or ad incommodum)

An example is as follows:-

The best way to eliminate the black money economy is to eliminate the condition that makes it possible

The use of a tangible medium of exchange (mainly cash) is a condition that makes black money possible


Therefore the best way to fight the black money economy is to abolish tangible medium of exchange

The major premise is that black market can be eliminated by removing the condition that makes it possible. For an argument even oxygen and living conditions on the planet is a necessary condition that makes black market possible. This is absurdity.

  1. Demonstrating an argument as False Dichotomy

The fallacy of false dichotomy is committed when the arguer claims that his conclusion is one of only two options, when in fact there are other possibilities. The arguer then goes on to show that the 'only other option' is clearly outrageous, and so his preferred conclusion must be embraced. Such an argument has relied on a false dichotomy as it falsely assumes that there are only two possible situations.

Either nations are with us, or they are against us in war against terrorism

Switzerland is not with us


Switzerland is against us.

The first premise does not admit of a situation where a nation may remain neutral. This is a false dichotomy.

An example of a valid dichotomy is as follows:-

  1. A is dead or he is alive

  2. A is not dead

  3. Therefore A is alive

The above is not a false dichotomy because the dichotomy is true. One can either be living or dead. In fact the definition of a dead person is one who is not living and there is no third state in which human beings can exist.

The concept, from both sides of the "debate," that science and religion are mutually exclusive and one cannot believe in both. The proposal is that science and religion describe entirely different things; science describes what is known and religion gives answers to what cannot be known. Moreover, people with faith may argue that science is a good explanation of what things like evolution and gravity are, but religion provides the answer for why they exist. Hence the dichotomy of science and religion is a false dichotomy.


It is not essential to be well versed in formal logic to be succeed as a judge or a counsel. However a ground knowledge would help in realising what are the basic mental processes that we go through when we pass adjudication orders or argue a case in a court of law. Ability to reason and argue is a necessary complement to knowledge of law in arguing cases as a counsel or writing a good judgment.


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