I need help to understand the following sentence:
人は誰でも正気ならば自己の行為について良心に責任を負う義務がある。
I understand that「自己の行為について良心に責任を負う義務がある」 means that in one's conscience, he has a duty to take responsibility for his actions.
However, I cannot figure out what the first part of the sentence means. In particular, I am confused by the following:
正気ならば
My dictionary tells me that ならば means "if possible" and 正気 means "true spirit". But "true spirit, if possible" doesn't make any sense to me.
Can anybody help me to understand this?