The Roman Catholic Church is the largest non-government provider of health care services in the world. It has around 18,000 clinics, 16,000 homes for the elderly and those with special needs, and 5,500 hospitals, with 65 percent of them located in developing countries. In 2010, the Church's Pontifical Council for Pastoral Assistance to Health Care Workers said that the Church manages 26% of the world's health care facilities. The Church's involvement in health care has ancient origins.Jesus Christ, whom the Church holds as its founder, instructed his followers to heal the sick. The early Christians were noted for tending the sick and infirm, and Christian emphasis on practical charity gave rise to the development of systematic nursing and hospitals. The influential Benedictine rule holds that "the care of the sick is to be placed above and before every other duty, as if indeed Christ were being directly served by waiting on them". But for centuries, Catholic health care was scientifically primitive. Different saints were invoked for every body part in the hope of miraculous cures. During the Middle Ages, monasteries and convents were the key medical centres of Europe and the Church developed an early version of a welfare state. Cathedral schools evolved into a well integrated network of medieval universities and Catholic scientists (many of them clergymen) made a number of important discoveries which aided the development of modern science and medicine.