This author and everyone else would do well to read the indicated book “On Conscience” by Joseph Cardinal Ratzinger which contains then Cardinal Ratzinger’s 1984 and 1991 talks on the subject of conscience which are excellent indeed. These have been reprinted in 2007 by Ignatius Press. Further many of now Pope Benedict XVI extensive lectures, homilies, and writings are filled with references to the subject. And no one does a better job in clarifying, simplifying, and making this or any subject pure joy to read and so understand.
Pope Benedict XVI is well known as “the conscience of our age” by thousands of his students, contemporaries, and those of us just discovering the great gift he is to our times and our Church since his earliest years.