Sometimes a question is the best response.
Answer: I am a true solipsist. (Gorgias)
Question: So why tell me?
A: There is no truth. (Gustave Flaubert)
Q: Is that true?
A: Knowledge is unknowable. (Francisco Sanches)
Q: How do you know?
A: It is irrational to assume that tomorrow will be anything like today. (David Hume)
Q: So you learned to speak, read, and write because…?
A: All cultures are equally valid. (Franz Boas)
Q: Including those that teach that all other cultures are invalid?
A: Truth is created, not discovered. (Friedrich Nietzsche)
Q: Did you just make that up?
A: There is no free will. (Baron d’Holbach)
Q: What makes you say that?
You see, every one of the “answers” above follow from valid, methodically reasoned logical arguments. But these narrow conclusions cannot stand beyond the boundaries of the premises that lead to them.