A fortiori

Hello friends welcome to series of Legal Maxims.

Introduction:

A legal maxim is an established principle or proposition of law. Legal maxims are generally in Latin language and are written in italics in a legal document.

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A fortiori orArgumentum a fortiori

Literal Meaning: from stronger.

Definition and Use: An a fortiori argument is an "argument from a stronger reason", meaning that, because one fact is true, a second (related and included) fact must also be true.

Argumentum a fortiori is a form of argumentation that draws upon existing confidence in a proposition to argue in favour of a second proposition that is held to be implicit in, and even more certain than, the first.

Examples

1. If a person is dead (the stronger reason), then one can with equal or greater certainty argue a fortiori that the person is being dead.

2. If driving 10 mph over the speed limit is punishable by a fine of $50, it can be inferred a fortiori that driving 20 mph over the speed limit is also punishable by a fine of at least $50.

3. If a teacher refuses to add 5 points to a student's grade, on the grounds that the student does not deserve an additional 5 points, it can be inferred a fortiori that the teacher will also refuse to raise the student's grade by 10 points.

Usage in Context:

Clearly, if laws depend so heavily on public acquiescence, the case of conventions is an a fortiori one.

In ancient Indian logic (nyaya), an inference derived from an a fortioripostulation is known as kaimutika or kaimutya nyaya, from the words kim uta meaning "even more so".

In Islamic jurisprudence, a fortiori arguments are proved utilising the methods used in qiyas (reasoning by analogy).

Types of a fortiori:

1)A maiore ad minus

In logic, a maiore ad minus describes a simple and obvious inference from a claim about a stronger entity, greater quantity, or general class to one about a weaker entity, smaller quantity, or specific member of that class:

1) From general to particular

e.g. What holds for all X also holds for one particular X.

2) From greater to smaller

e.g. a) If a door is big enough for a person two metres high, then a shorter person may also come through;

e.g. b) If a canister may store ten litres of petrol, then it may also store three litres of petrol.

3) From the whole to the part

e.g. If the law permits a testator to revoke the entirety of a bequest by destroying or altering the document expressing it, then the law also permits a testator to revoke the portion of a bequest contained in a given portion of a document by destroying or altering that portion of the document.

4) From stronger to weaker

e.g. If one may safely use a rope to tow a truck, one may also use it to tow a car.

2) A minore ad maius

The reverse, less known and less frequently applicable argument is a minore ad maius, which denotes an inference from smaller to bigger.

In law

Argumentum a maiori ad minus(from the greater to the smaller) – works in two ways:

Way 1) who may more, all the more so may less, and relates to the statutory provisions that permit to do something.

Way 2) who is ordered more, all the more so, is ordered less, and relates to the statutory provisions that order to do something.

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