He provides this example: "Clearly, if laws depend so heavily on public acquiescence, the case of conventions is an a fortiori [read even more compelling] one.
[5] In Islamic jurisprudence, a fortiori arguments are proved utilising the methods used in qiyas (reasoning by analogy).
[6] Consider the case where there is a single necessary and sufficient condition required to satisfy some axiom.
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:[9] The reverse, less known and less frequently applicable argument is a minore ad maius, which denotes an inference from smaller to bigger.
[10] "Argumentum a maiori ad minus" (from the greater to the smaller) – works in two ways: An a fortiori argument is sometimes considered in terms of analogical reasoning – especially in its legal applications.