(playing devil's advocate) At what stage is it appropriate to care "too much" about safety? Is it okay to be enthusiastic about an invasive-and-unproven techn

(playing devil's advocate) At what stage is it appropriate to care "too much" about safety? Is it okay to be enthusiastic about an invasive-and-unproven technology when you're dreaming up pie-in-the-sky use-cases and are raising money? Is it okay to stay enthusiastic in the cold-light-of-dawn moment when you realize you're going to have to kill a bunch of animals to make any progress? Is it okay to force yourself to be enthusiastic after all your initial tests reveal that this idea is, in fact, infeasible?