Diagram MAPD0533

Venus Mercury overlain: This diagram is not prescribed by the text of Macrobius. The dual planetary order resulting from the diagram is nowhere in the text of Macrobius. The pattern of intersecting circles is a medieval interpretation of Macrobius's text describing two distinct and separate planetary orders (I.xix.1-9), the Caldean and the Egyptian. Macrobius definitely considers the Egyptian order, which he calls Platonic, correct. He considers the Caldean order, which is also that of Pliny and Ptolemy, to be incorrect. According to Macrobius, only one order (Platonic) should ever appear; in ascending sequence from the earth it is: Moon - Sun - Mercury - Venus - Mars - Jupiter - Saturn. Macrobius only describes a pattern of concentric planetary circles. The pattern of intersecting circles is a medieval invention which allows both the Caldean and the Egyptian orders to exist. The difference between the two appears with the location of the two inner planets, Mercury and Venus. Contrary to the Egyptian order, the Caldean order places these two immediately below the Sun, rather than above it. The basic type of intersecting-circles diagram puts three planets on three circles, equal in size, each intersecting the other two, with the centers of the three circles on a single straight line and with the two outer centerpoints equidistant from the middle centerpoint. The resulting pattern of intersections produces a common middle space that is part of each of the three circles. This arrangement of intersecting circles explains the changing order of the inner planets. The three planets on these circles are the Sun, Mercury, and Venus. When the centers of the intersecting circles are set on a vertical line, Venus is on the top circle, Mercury is on the middle circle, and the Sun is on the lowest circle. With all planets at their uppermost positions, the order from outermost towards the middle is Venus - Mercury - Sun. At their lowest positions the order is reversed, with the Sun being farthest from the middle of the diagram, and Venus being closest to the middle. The common middle section of the intersecting circles is typically the location of the moon's circle and the earth, both of which the three intersecting circles enclose. Either the moon or the earth or both or neither may appear in the middle section of the diagram in the MSS. The diagrams of intersecting circles normally appear marginally, next to the text. Their most common context is the text of Macrobius but they often appear with the text of another author, e.g., Capella or Calcidius. They are, of course, a standard part of William of Conches's Philosophia, written in the twelfth century; this catalogue does not list diagrams in the MSS of the Philosophia. Most attributes of these diagrams are described briefly in ordinary language. The following abbreviations are used in the list of attributes for the Macrobian intersecting-circles diagrams: marg = appears in the margin of the text (number) of circles = the number other than three of intersecting circles letters V, M, S = these stand for Venus, Mercury, Sun