dilemmas, psychological problems, illness, taking care of older generations, unemployment, marital holiness and virtue, common prayer, religious discussions and more. He accepted the rhythm method as a moral form of family planning, although only in limited circumstances, within the context of family. Theology and science To Pius XII, science and religion were heavenly sisters, different manifestations of divine exactness, who could not possibly contradict each other over the long term. Regarding their relation, his advisor Professor Robert Leiber wrote: "Pius XII was very careful not to close any doors prematurely. He was energetic on this point and regretted that in the case of Galileo." Evolution of the human body In 1950, Pius XII promulgated Humani generis, which acknowledged that evolution might accurately describe the biological origins of the human form, but at the same time criticized those who "imprudently and indiscreetly hold that evolution ... explains the origin of all things". Catholics must believe that the human soul was created immediately by God. Since the soul is a spiritual substance, it is not brought into being through transformation of matter, but directly by God, whence the special uniqueness of each person. Fifty years later, Pope John Paul II, stating that scientific evidence now seemed to favour the evolutionary theory, upheld the distinction of Pius XII regarding the human soul. "Even if the human body originates from pre-existent living matter, the spiritual soul is spontaneously created by God." Capital punishment In an address given on 14 September 1952, Pope Pius XII said that the church does not regard the execution of criminals as a violation by the State of the universal right to life: When it is a question of the execution of a condemned man, the State does not dispose of the individual's right to life. In this case it is reserved to the public power to deprive the condemned person of the enjoyment of life in expiation of his crime when, by his crime, he has already disposed himself of his right to live. The church regards criminal penalties as both "medicinal", preventing the criminal from re-offending, and "vindictive", providing retribution for the offense committed. Pius defended the authority of the State to carry out punishment, up to and including the death penalty. Democracy and monarchy Pius XII taught that the masses were a threat to true democracy. In such a democracy, liberty is the individual's moral duty and