subtle argument

That is a subtle Argument, seldom made Use of but by Unbelievers.

Little by little the subtle argument is so advanced that the degradation once feared is no longer to be seen.

See his subtle argument, Principles of Human Knowledge, part i. sec.

The kidnappers could not follow the subtle argument of the Greek, but they began to look dangerous.

The inference a juryman might draw from this question and answer would constitute a subtle argument upon that branch of the case.