Passage Summary: Tom says ignoring the past is fine because it worked before. Mary points out a specific difference: the past cases involved old rules, while today's cases involve new ones, which changes the outcome from harmless to harmful.

Conclusion: Mary concludes that the recent overturning of legal rulings is detrimental because it makes the law appear unstable.

Reasoning: Mary distinguishes between the 'old' precedents that were historically overturned and the 'recent' rulings being overturned now, arguing the latter causes harm that the former did not.

Analysis: Mary’s method of reasoning relies on making a factual distinction to undermine Tom’s generalization. Tom uses a 'what was true then is true now' logic, but Mary points out that the 'then' and the 'now' are not actually comparable because the age of the precedents differs. When identifying her method, look for an answer choice that describes her pointing out a relevant difference between the historical examples Tom cites and the current situation he is trying to dismiss. She is essentially narrowing the scope of his evidence to show it doesn't support his broad conclusion.