How is the term "a fortiori" best understood in legal terms?

The term "a fortiori" is a Latin expression that translates to "from the stronger." In legal contexts, it denotes a form of reasoning that asserts that if something is true in one scenario, it must also be true in another, more persuasive scenario. When legal arguments are made a fortiori, they leverage a stronger premise to justify a conclusion or outcome, implying that if a particular legal principle applies in one instance, it logically follows that it applies even more strongly in another situation.

For example, if the law provides certain protections for a specific class of individuals, a fortiori reasoning would argue that those same protections should apply with even greater justification to a different class that faces a more severe risk. This concept bolsters arguments by demonstrating that the rationale holds true not just in a baseline scenario but under more significant or similar circumstances, hence the reasoning is referred to as being for "stronger reasons."