  For Ockham, a demonstration arising from natural efficient causes takes the following pattern: “When there is no opaque medium between the moon and the sun, the moon will be illuminated by the sun, when the moon is in such a place, there will be no opaque medium between the moon and the sun; therefore the moon is then illuminated.” Here, the attribute “illuminable,” an attribute predicated of its subject without further determination, is indemonstrable, but the attribute “illuminated when in such a place” is predicated of its subject with a further determination, and so can be demonstrated. This form of demonstration agrees closely with the highest form of demonstration in Albert and Giles of Rome, but Ockham does not regard it as demonstration of the highest sort, since its conclusion is hypothetical rather than categorical.