The growth of a healthy population was made possible by the reformation of family life, which was one of the greatest achievements of Christianity in the social sphere. In the early days of the Church the institution of the family had been reconstituted by moderating the harshness of the Roman domestic rule (_patria potestas_), by raising the moral and social position of women, and by reforming the system of testamentary and intestate successions; and the great importance which the early Church attached to the family as the basic unit of social life remained unaltered throughout the Middle Ages.[5] [Footnote 5: Troplong, _De l'Influence du Christianisme sur le Droit civil des Romains_; Cossa, _Guide_, p. 99; Devas, _Political Economy_, p. 168; Périn, _La Richesse dans les Sociétés chrétiennes_, i. 541 _et seq._; Hettinger, _Apologie du Christianisme_, v. 230 _et seq._] The Middle Ages were therefore a period when the production of wealth was looked upon as a salutary and honourable vocation. The wonderful artistic monuments of that era, which have survived the intervening centuries of decay and vandalism, are a striking testimony to the perfection of production in a civilisation in which work was considered to be but a form of prayer, and the manufacturer was prompted to be, not a drudge, but an artist. In the Middle Ages, however, as we have said before, man did not exist for the sake of production, but production for the sake of man; and wise consumption was regarded as at least as important as extended production. The high estimation in which wealth was held resulted in the elaboration of a highly developed code of regulation as to the manner in which it should be enjoyed. We do not wish to weary the reader with a repetition of that which we have already fully discussed; it is enough to call attention to the fact that the golden mean of conduct was the observance of liberality, as distinguished, on the one hand, from avarice, or a too high estimation of material goods, and, on the other hand, from prodigality, or an undue disregard for their value. Social virtue consisted in attaching to wealth its proper value.