- Our not wanting to die is a bit of irrational behavior selected for by evolution. The universe doesn’t care if you’re there or not. The contrasting idea that you are the universe is mystical, not rational.
- The idea that you are alive “now” but will be dead “later” is irrational. Time is just a persistent illusion according to relativistic physics. You are alive and dead, period.
- A cyber-replica is not you. If one were made and stood next to you, you would still not consent to be shot.
- Ditto a meat replica
- If you believe the many worlds model of quantum physics is true (Eliezer does), then there already are a vitually infinite number of replicas of you already, so why bother making another one?
Terminal values and preferences are not rational or irrational. They simply are your preferences. I want a pizza. If I get a pizza, that won't make me consent to get shot. I still want a pizza. There are a virtually infinite number of me that DO have a pizza. I still want a pizza. The pizza from a certain point of view won't exist, and neither will I, by the time I get to eat some of it. I still want a pizza, damn it.
Of course, if you think all of that is irrational, then by all means don't order the pizza. More for me."
If the person was capable of learning (it's not always so, particularly for older people), I'd start with explaining specific errors in reasoning actually exhibited by such confused replies, starting with introducing the rationalist taboo technique (generalized to assuring availability of an explanation of any detail of anything that is being discussed).
Here, we have overuse of "rational", some possibly correct statements that don't seem related ("Our not wanting to die is a bit of irrational behavior selected for by evolution. The universe doesn’t care if you’re there or not."), statements of outright unclear motivation/meaning/relevance ("The contrasting idea that you are the universe is mystical, not rational."). Then, some feign-sophisticated rejection of statements of simple fact ("The idea that you are alive “now” but will be dead “later” is irrational.").
(This won't work well in writing, you need to be able to interrupt a lot.)