should commit a certain proportion of their GNP in aid to the developing world, and she also spoke of the need for institutions to enable and manage both 'aid and trade'. This was a practical as well as an ethical concern: Ward believed such policies would encourage stability and peace. She is sometimes called a "distributist". Environmental concerns Ward started to see a close connection between wealth distribution and conservation of planetary resources. "… the careful husbandry of the Earth is sine qua non for the survival of the human species, and for the creation of decent ways of life for all the people of the world." She used the phrases "inner limits and "outer limits" to refer to the inner limits of the human right to an adequate standard of living and the outer limits of what the Earth can sustain. In 1966, she published Spaceship Earth and is sometimes said to have coined the phrase. Ward is seen by some as a pioneer of sustainable development. She and René Dubos, co-authors of Only One Earth (), have been described as "parents" of a concept which "did not know its own name at first". Only One Earth: The Care and Maintenance of a Small Planet was written for the 1972 UN Stockholm conference on the Human Environment. The report was commissioned by Maurice Strong, secretary general of the United Nations Conference on the Human Environment. Ward's work was rooted in her sense of morality and Christian values. She saw care of the environment and concern for the well-being of all humankind as a "dual responsibility", especially for anyone sharing her religious outlook. At the same time, she believed wealth distribution combined with conservation was essentially a rational policy: "We are a ship's company on a small ship. Rational behaviour is the condition of survival." In 1971 she founded the International Institute for Environment and Development (IIED), acting as president from 1973 and chairman from 1980. Later life Ward had recovered from cancer in the late 1940s thanks, she believed, to the spiritual support of Padre Pio. The illness recurred twenty years later but surgery did not cure her. In 1973 she retired from Columbia University where she had been Schweitzer Professor of Economic Development for the previous five years and went to live in Lodsworth, Sussex. The next year she was made a Dame Commander of the Order of