As is well known, one is to die rather than murder a Jew, perform adultery and the like, or worship an idol (Sanhedrin 74a). Is blasphemy (i.e. denying one's dedication to the Torah) permissible to save one's life?
I think I remember seeing somewhere that one actually is to give over their life before denying the Torah or even that they are a Jew, since I don't remember the place, hard for me to determine if this was talking about a hypothetical situation (i.e. die before touching a lady that is niddah etc.) or l'maiseh