ArgumentMedieval authors adopted a range of postures when writing about the role of reason in matters of faith. At one extreme, the phrase “natural theology” was used, largely pejoratively, to connote something clearly inferior to revealed theology. At the other end, there was also a long tradition of what one might term “the impulse to natural theology,” manifested perhaps most notably in the embrace of Nature by certain twelfth-century authors associated with the school of Chartres. Only in the fifteenth century (...) does one find authors using natural reason to investigate religious truths who also employ the term “natural theology,” now in a positive light, for their activities. Among such thinkers, astrology and eschatology frequently played an important role. In that respect, the writings of fourteenth-century Bolognese jurist John of Legnano offer an important example of the place of astrological, prophetic, and apocalyptic material in late medieval natural theology. In his 1375 treatise De adventu Christi, Legnano demonstrated that ancient poets, pagan seers such as the Sibyls, and non-Christian astrologers had all predicted, like Old Testament prophets, the virgin birth of Christ. For Legnano, not simply was Creation part of God's revelation, but, equally importantly, the very categories of reason and revelation blur in a way that points toward the works of Renaissance humanists and lays a foundation for a model of natural vaticination that showed reason's capability to reach fundamental religious truths. (shrink)

At some time between 1375 and 1378 the Bologna jurist John of Legnano composed a judgement on the conjunction of Saturn and Jupiter in October 1365. One of a number of contemporary authors offering...

In the 1480s Dominican humanist Filippo de’ Barbieri published an illustration of a supposedly ancient female seer called the ‘Sybilla Chimica’, whose prophetic text repeated the words of the ninth-century astrologer Abu Ma‘shar. In tracing the origins of Barbieri’s astrological Sibyl, this article examines three sometimes interlocking traditions: the attribution of an ante-diluvian history to the science of the stars, the assertion of astrology’s origins in divine revelation, and the belief in the ancient Sibyls’ predictions of the birth of Christ (...) and other Christian truths. Medieval authors from the twelfth century on began to cite these traditions together, thereby simultaneously authorizing the use of astrology to predict religious changes and blurring the categories of natural and supernatural as applied to human understanding. This blending of astrology and prophecy appears notably in works by such authors as John of Paris, John of Legnano, Johannes Lichtenberger, and Marsilio Ficino. Ultimately the trajectory that produced Barbieri’s astrological Sibyl would lead to a wave of astrological apocalyptic predictions in the sixteenth and seventeenth centuries, as well as to the harnessing of astrology for the defense of the faith in the form of an astrological natural theology, sacralizing science as well as nature. (shrink)