Surely noone is going to disagree with the statement "Our conscience can be wrong".

There've been too many cases of people doing horrible things in the conviction that they are right. I have no doubt at all that the suicide hijackers of September 11 were sure that they were acting in good conscience.

And that's just one example where it's easy enough to agree thatbthey got it devastatingly wrong.

At the end of the day, after you've done what you can to check whether what your consience tells is right is in reality right, "informing your conscience" as they say, the right thing to do is to follow that informed consience. But it can still be wrong even then.