The Middle Ages are reckoned to run from the fourth or fifth century CE to the middle or end of the fifteenth century CE. A period of nearly 1.000 years naturally saw a great deal of change, not only politically, but also intellectually. In Western and Central Europe at least, the first part of the Middle Ages (until the eleventh century), is known as the Dark Ages, when the relative political and economic backwardness of society, which followed the collapse of the Roman Empire in the west and the breakdown of the Mediterranean world, was reflected in an apparently impoverished intellectual culture. Few writings of any kind survived from this period, and ancient writers like Plato and Aristotle seem to have been little read.
From the eleventh century onward, there was a political and economic revival that extended to intellectual fields. The revival entailed the establishment of universities, increased availability and translation of texts from Arabic and Greek, and an increase in new writing. The works of Aristotle were mostly translated during the twelfth century, and subsequently, most fields of intellectual activity, including psychology, were heavily influenced by these translations.
By the beginning of the ninth century, Islam had established itself in the Middle East, North Africa, and Spain, and intellectual activity flourished in these lands, although it languished in most of Europe. Islamic scholars discovered Aristotle’s works well before Western Europeans, and quickly produced innovative thinking of their own. Many of the works of these scholars, such as Ibn Sina (980-1037 CE) and Ibn Rushd (1126-1198 CE), were translated into Latin and widely read by later Europeans.
Whereas Europe was politically fragmented throughout the Middle Ages, the Christian Church provided a unifying force, and Latin was the language of intellectual activity in Europe just as Arabic was throughout Islam. In the twentieth century the Church was often thought to have exercised a stultifying if not downright repressive effect on medieval thinking in Europe, but in fact, the various institutions of the medieval Church were largely staffed by intellectuals who tended to regard the activities of other intellectuals liberally. One instance of this attitude is the respect that Christians accorded to the writings of Islamic scholars like Avicenna and Averroes, as Ibn Sina and Ibn Rushd were known in the West, or the Jewish philosopher Maimonides (1135-1204 CE). Medieval thinking about psychology seems to have been truly international.
It is also worth noting that the medieval Church helped set up many of the new European universities, tried to ensure that people consented to their marriages, and campaigned vigorously on a variety of children’s welfare issues. On the other hand, almost all the medieval scholars, whether Christian, Islamic, or Jewish, were adherents to their religion and often sought to relate their religious views with their views on other subjects.