The controversy roused by the Pope’s address last autumn to Italian obstetricians was at its height when on a Sunday evening I sat listening to the second of Lord Radcliffe’s Reith Lectures. His scholarly exposition of the natural law seemed to silence the din of ill-informed and sentimental criticism which had assailed the Holy Father’s calm and authoritative statement of moral judgments which were the ordinary teaching of the Church. It was not that Lord Radcliffe stood forth as a champion of natural law; the pleasure one felt was due merely to this reminder of a concept which had been the corner-stone of ethics for a millennium. For the attack on the Pope’s teaching in this particular allocution, like the modem propaganda in favour of birth control and euthanasia, of divorce and artificial insemination, was made in ignorance or in contempt of that fundamental law of nature which in fact governs most of these grave problems. That law goes almost unrecognised outside the Catholic Church. It seems opportune, therefore, to introduce this series of articles in Blackfriars with an account of the natural law and its relationship with law in general.

The word ‘law’ is used in a variety of senses today. It may mean the decree of a legislator, usually the human ruler, regulating the external conduct of the human subject; or it may mean a scientific law, like the law of gravitation, which is regarded as merely the expression of the behaviour of inanimate objects as discerned by a process of induction from observation and experiment.

But the medieval mind took a wider sweep, and subsumed under the name ‘law’ all these various meanings. First of all it considered the eternal law which was the plan of the all-wise Creator for the harmonious progress of the whole universe of his creation.