Final answer:
The speaker might use a pathos appeal by sharing powerful stories about the positive impact of 12-step programs on specific individuals.
Step-by-step explanation:
An addiction therapist speaking at a professional conference might use a pathos appeal by sharing several powerful stories about how 12-step programs like Narcotics Anonymous saved the lives of specific people struggling with addiction.
By highlighting the personal experiences and positive outcomes of individuals who have benefited from these programs, the speaker aims to evoke emotions and empathy in the audience, reinforcing the idea that these programs are doing more good than harm.