Influences outside Persia
Wilczynski (1959) and Joseph Spengler (1971) have brought to our attention that medieval Persian scholar/scientist Abu Rayhan Biruni, who lived some nine centuries before Thomas Malthus and Charles Darwin, can be regarded as their precursor in the book he wrote on India.
According to Spengler, Biruni had acknowledged that: “since the growth of man's numbers is limited by the capacity of the environment to provide support, the earth could become overpopulated and in need of a thinning of its numbers.” According to Biruni's book on India, the growth of anything is limited by the environment accessible to it. And, since the capability for the growth of a species in number is unlimited, its actual growth is restrained by limiting and almost exclusively external agents. As suggested by Spengler, Biruni observed, as did Darwin upon reading Thomas Malthus, that the pressure of increasing numbers will give rise to natural selection.Biruni was not the only medieval Persian-speaking Muslim scholar with a “Malthusian” population theory centuries before Malthus. In fact, all the three Persian ethicists, i.e. Ibn Miskaway, Nasir Tusi, and Asaad Davani, held similar views after Biruni. In fact, these three ethicists even utilized mathematical calculations to demonstrate their population theories.
As the previously mentioned statement by George O'Brien indicates, medieval Christian/ Western European scholars did not contribute very much towards economic analysis. Beginning with the British economist William Ashley in the late nineteenth century, many historians of economics, ignoring the contributions of Iranians, assumed that economic analysis which, to them, had ended with the demise of the golden age of Greek civilization, was revived in Western Europe beginning with the genius of Thomas Aquinas, in his seminal book Summa Theologica.
However, while no one can deny the significance of Summa Theologica, it is also undeniable that he and other Christian scholars were very much influenced by medieval Muslims, in particular by Persian scholars.
After all, as suggested by the historian of the Middle Ages P. Hitti (1943), medieval Muslim scholars, in particular Persian-speaking ones, were: “bearers of the torch of culture and civilization throughout the world” (ibid., 143). In fact, medieval Persian-speaking scholars such as Ibn Sina, Farabi, and Ghazali, along with the medieval Spanish Muslim Ibn Rushd (Averroes), influenced pre-Renaissance European scholars in various ways, including by introducing them to Greek/Aristotelian rationalism, which had been preserved by Muslim thinkers.In fact, as W.M. Watt has argued, Aquinas and other European scholars had to learn all they could from medieval Persian and other Muslim scholars before they could make further advances in various fields of inquiry (Watt, 1972, 43). According to Abbas Mirakhor (1988), many medieval Christian scholars borrowed, explored, assimilated, and elaborated the writings and teachings of medieval Persian and other Muslim scholars. Robert Hammond (1947) has demonstrated the extent of this borrowing/assimilation by placing some of the arguments of Thomas Aquinas opposite those of Persian-speaking Farabi and showing that they are virtually the same (ibid., 41). The translations of the works by Persians and Arabs had a substantial influence on West-European thinkers. This explains why Gordon Leff has noted that: “Intellectually, the difference between the twelfth and thirteenth century was, at its broadest, the difference been isolation from the Islamic world and contact with it” (1958, 141).
Philosopher of science S.H. Nasr (1970) has demonstrated the influence of particular medieval Persian-speaking Muslims on Europe that affected further developments in various sciences. For various reasons those influences were even greater regarding economic ideas. According to Abbas Mirakhor, if those ideas of Persian/Arab Muslims:
in philosophy and science reached the scholars through the translation of their works, the economic ideas had two other channels of entry into the medieval way of life. One such channel was trade and the other was the cultural diffusion of Muslim economic institutions and processes into European medieval societies.
(Mirakhor, 1988, 329)