“Someone, in fact, has suggested such is the case. Except that the needle doesn’t point precisely in the direction of the daystar, but toward the intersection of the celestial meridians. A sign that, as has been said, ‘hic lapis gerit in se similitudinem coeli,’ and the poles of the magnet receive their inclination from the poles of the sky, not from those of the earth. Which is a fine example of movement provoked at a distance, not by direct material causality: a problem that my friend John of Jandun is studying, when the Emperor does not ask him to make Avignon sink into the bowels of the
...more
