Conscience is about *meaning* and *values* - not reality as you define it. Please go back to Thomistic philosophy/theology - your point is so skewed it is laughable.
Guess what - truth can be found in grayness - it is not just black and white or rigid. What you describe; some of us would call that moral relativism.
http://www.natural-law-and-conscience.org/readings/haring.asp
"The object of right is the common welfare. But the common welfare includes also a very extensive domain which is concerned with the protection and nurture of individual welfare. And this includes above all the creation of an external moral climate which makes it possible for the individual and the group to attain the moral religious ideal. Right must therefore serve not only naked justice, but morality as such, though always with a view toward justice.   
...in its application a law or right of our nature can be robbed of its binding force through a change of nature (not mere external reality)"