What constitutes "full knowledge" in the case of Mortal Son?

I am having a discussion with some others who believe that mortal sin is impossible because one could never have full knowledge. Exactly how much knowledge is required? What must we be knowledgable about?

This link should answer your question about the conditions of mortal sin. If you have any further questions or concerns that are not answered by this link, please contact Catholic Answers directly.

Recommended Reading:
What is meant by “full knowledge”?

DISCLAIMER: The views and opinions expressed in these forums do not necessarily reflect those of Catholic Answers. For official apologetics resources please visit www.catholic.com.