This commandment is binding on every man, and the interpretation of it given in the Catechism is doubtless the correct one. It thus becomes binding on the conscience of the Christian to abstain from that which tends toward the unjust destruction of his own life, or that of his neighbor, that is, from that which is harmful to the body. But we should not that the decision whether a particular act is harmful must be made by the individual concerned. To deny this means to make science, instead of God, the Lord of the conscience. The Christian is required by God to separate from what is sinful.
Scripture alone can demonstrate that a given course of conduct is sinful.
Natural revelation cannot be regarded as a fuller revelation than Scripture, or as coordinate with Scripture in any sense whatever. 4. It is possible that science or experience may show that certain conduct is harmful. Science or experience can never show that anything is sinful. Scripture teaches that what is really harmful is ordinarily sinful. The decision whether science or experience shows that particular conduct is harmful must be made by the individual concerned, not by other persons.