Methods and Purposes of Definition

Definition by operation, also called operational definition. Stating a test that decides whether the term applies. "A solution is acidic if it turns blue litmus red." The definition is a procedure, and its virtue is that it settles every case that arises.

Definition by genus and differentia. The traditional form at sequence 550, and the most powerful of all, because it places the thing and distinguishes it in one statement.

The strength of the family. A connotative definition reaches cases nobody has thought of, which is exactly what a denotative one cannot do.

The weakness. It is harder to draft, easier to get wrong, and it exposes the drafter's choices to argument in a way a list does not.

How a statute uses both, and why

This is the practically useful part of the chapter.

A definition clause that says "means" is normally connotative, giving genus and differentia, and it is exhaustive: the term covers whatever satisfies the attributes and nothing else.

A definition clause that says "includes" is normally denotative, adding named members or subclasses to whatever the term already covers, and it is enlarging rather than exhaustive.

A clause that says "means and includes" does both, and courts read it as exhaustive with the listed items placed beyond argument.

A Schedule is pure enumeration. Where an Act applies to the establishments listed in a Schedule, the class is fixed by the list, and the most similar establishment in the country is outside it until the Schedule is amended.

Illustrations are ostensive. The illustrations to a section display members of the class so that a reader can see where the line runs. They guide and they do not control, precisely because they are extensional and the section is intensional.

Section 2(1)(d) of the Bharatiya Sakshya Adhiniyam 2023 does all of this in one definition, and it is worth reading as a specimen. It first states attributes: any matter expressed or described or otherwise recorded upon any substance by means of letters, figures or marks or by any other means, intended to be used or which may be used for the purpose of recording that matter. That is genus and differentia. It then adds, by "includes", electronic and digital records. And it then supplies six illustrations: a writing, words printed, lithographed or photographed, a map or plan, an inscription on a metal plate or stone, a caricature, and electronic records on emails, server logs, computers, laptops or smartphones, messages, websites, locational evidence and voice mail. Connotative core, denotative extension, ostensive illustration, in that order, and each doing a different job.

Methods, kinds and purposes together

MU asks for all three in one topic, and the way they fit is worth a paragraph, since a question on 4.3 in MU's own words wants it.

The purpose comes first, from sequence 540: what is this definition for?

The purpose settles the kind, from sequence 570: to create a usage is to stipulate; to report one is to be lexical; to sharpen one is to précise.

The kind and the subject matter settle the method. A stipulative definition of a technical term is usually connotative, by genus and differentia. A précising definition of a class of establishments may be denotative, by Schedule, because the drafter wants certainty more than flexibility. A lexical definition of a quality that cannot be described may have to be ostensive.

And the method carries a cost. Choosing enumeration buys certainty and loses reach. Choosing genus and differentia buys reach and invites argument. There is no method that has both, and a drafter's choice is always a trade between them.

A worked example

An Act is to define "hazardous industry".

Method one, enumeration by Schedule. List the industries. Certain, easy to apply, and out of date the day a new process is invented. Every genuinely dangerous industry not listed is outside the Act.

Method two, genus and differentia. "Hazardous industry means any industry involving the use, storage or handling of a substance which by reason of its toxicity, inflammability or explosiveness is likely to cause injury to persons or damage to property." Reaches processes nobody has thought of. Generates litigation about "likely", about "substance" and about the degree of hazard required.

Method three, operational. "An industry is hazardous if the prescribed authority, on the prescribed tests, so certifies." Settles every case, and transfers the whole question to an authority, which is a decision about who decides and not only about what the word means.

Method four, and the one real statutes usually take: all three. A connotative core, a Schedule of industries deemed to be within it, and a power in the Government to add to the Schedule. The core gives reach, the Schedule gives certainty for the known cases, and the power keeps the Schedule current.

What the example teaches. The methods are not rivals to be chosen between once. They are tools with different costs, and a well drafted definition uses more than one because no single method buys both certainty and reach.

Distinctions that carry marks

What this does not mean

Ostensive definition is not childish. It is the only method available for a quality that cannot be described, and expert evidence frequently proceeds by it.

Enumeration is not lazy drafting. It buys certainty, which is sometimes worth more than reach, and a Schedule with a power of amendment is a considered design.

A synonym is not a definition of the term for someone who does not know the synonym. It moves the problem, and where the synonym is itself doubtful it is an instance of obscurum per obscurius from sequence 560.

Quick revision

Two families: denotative, working on extension, and connotative, working on intension.

Denotative methods: by example or ostension; by enumeration, which MU calls EXTENSIVE definition; by subclass. Clear, and silent about whatever they did not name.

Connotative methods: by synonym, which MU calls BIVERBAL definition; by operation; by genus and differentia. Reach unforeseen cases, and expose the drafter's choices.

In statutes: "means" is connotative and exhaustive; "includes" is denotative and enlarging; a Schedule is enumeration; illustrations are ostensive and do not control.

Section 2(1)(d) of the Bharatiya Sakshya Adhiniyam 2023 is the specimen: connotative core, denotative extension by "includes", then six illustrations.

Purpose settles the kind; kind and subject matter settle the method; and every method trades certainty against reach.

Test yourself

1. Name the two families of method and the methods in each.

The denotative or extensional family defines by indicating the objects the term applies to, and its methods are definition by example or ostension, definition by enumeration, and definition by subclass. The connotative or intensional family defines by stating the attributes the term implies, and its methods are definition by synonym, operational definition, and definition by genus and differentia.

2. What is the characteristic weakness of the denotative methods?

That they say nothing about anything they did not name. A person shown three examples must still decide the fourth case unaided, and a list leaves outside it the most similar item in the world until the list is amended. Extension cannot fix intension, which is why a denotative definition of a general term always leaves the boundary undetermined at exactly the point where it matters.

3. Distinguish a statutory definition using "means" from one using "includes".

"Means" is normally connotative and exhaustive: it states the attributes, and the term covers whatever has them and nothing else. "Includes" is normally denotative and enlarging: it adds named members or subclasses to whatever the term already covers, leaving the ordinary meaning intact. A great deal turns on which is used, since the first closes the class and the second opens it.

4. What does an operational definition do, and what does it cost?

It states a test that decides whether the term applies, so that every case which arises can be settled by carrying out the procedure. Its cost is that it transfers the substance of the question to whoever performs the test: a definition making an industry hazardous if a prescribed authority so certifies has decided who decides, which is a different matter from deciding what the word means, and it may leave the term with no content a court can review.

5. Analyse section 2(1)(d) of the Bharatiya Sakshya Adhiniyam 2023 as a specimen of method.

It has three layers. A connotative core states the attributes: any matter expressed, described or recorded on any substance by letters, figures, marks or any other means, intended or capable of being used to record that matter. A denotative extension then adds electronic and digital records by the word "includes". And six illustrations follow, ostensively displaying members of the class: a writing, printed words, a map, an inscription on metal or stone, a caricature, and electronic records on servers, devices and websites.

7. What is an extensive definition, and what is a biverbal definition? Give an example of each.

An extensive definition, which is definition by enumeration, fixes a term by listing the members of its class: "planet means Neptune, Mars, Earth, Jupiter and Saturn". It is denotative, since it works on the extension of the term. A biverbal definition, which is definition by synonym, fixes a term by giving another word of the same meaning: "sayonara means goodbye in Japanese", or "nullity means invalidity". It is connotative, and it is useless to a reader who does not already know the second word.

6. How do purpose, kind and method fit together?

The purpose comes first and settles what the definition is for. The purpose then settles the kind: creating a usage is stipulation, reporting one is lexical, sharpening one is précising. The kind together with the subject matter settles the method: a technical term is usually defined connotatively, a class of establishments may be defined by enumeration for certainty, and a quality that cannot be described may have to be shown. Each method trades certainty against reach, and no method buys both.