If conscience were really a supernatural guide to right conduct it would always and everywhere tell man what is eternally right or eternally wrong.
But conscience is changeable and uncertain. It is a magnetic needle that points North at one time and South at another time; that points East on one ship and West on another ship; that points all round the compass for all kinds of travellers on life's ocean; that has no relation to the everlasting truths at all.
Sceptics have pointed out that "conscience is geographical"; that it gives different verdicts in different countries, on the same evidence.
But I shall show that conscience is:
1. Geographical: that it is not the same in one country as in another.
2. Historical: that it is not the same in one age as in another.
3. Personal: that it is not the same in one person as in another.
4. Changeable: it alters with its owner's mind.
And that, therefore, conscience is not a true and certain guide to right, and cannot be the voice of God.
First, as to geographical, or local, conscience. The English conscience looks with horror or disgust upon polygamy, child murder, cannibalism, and the blood feud.