Suppose someone argues, “These two things look similar, so their legal rulings must be identical.” This is incomplete. A proper analogy requires an original case, a new case, the established original ruling, and a legally recognized operative cause shared by both.
Five checks follow: Does it oppose an authoritative text? Does it alter the textual ruling? Is the original rule amenable to causal reasoning? Is the shared attribute legally relevant? Does the new case already have its own textual rule? Failure at any of these stages undermines the proposal.
Broad similarities such as “both are beneficial” or “both may harm” are insufficient unless the proposed cause is precise and appropriately connected to the ruling.