An argument runs: “A particular discharge invalidates ablution because something leaves the body; therefore every bodily discharge invalidates ablution.” Here the alleged common attribute is so broad that its legal significance must be demonstrated.
First, on what proof is the original ruling established? Second, does that proof establish “every kind of exit” as the operative cause, or is this only an observed feature? Third, does the same legally effective cause exist in the new case?
Conclusion: Physical resemblance between two events does not complete a legal analogy. The cause and its authority must be established.