Pal.lat.984

...the other principles of this art. For Goodness is a substantial principle in this reasoning: namely, that the good, by reason of the goodness of the substance, performs a substantial good, and that substance is substantially good. Goodness is an accidental principle when the good performs an accidental good by reason of accidental goodness. For this accidental good within a substance is good, just as the [opposite] operation is evil. In scholastic philosophy, "substance" is the essence of a thing that exists by itself, while an "accident" is a quality that exists only within a substance (like the color of a rose). The reason why goodness is placed within this very science is so that it may be one of its principles, in which it serves as a general principle. Indeed, it is "general" so that good conditions may be created under that same goodness, and so that knowledge may be gained concerning specific goods which remain hidden within other general principles, in which they shine and appear by the persistence of goodness in those principles and vice versa, according to the practice of this art.

What Greatness is

Concordance, Quiddity Quiddity is a technical term for the "whatness" or essential nature of a thing.

Greatness is a being by reason of which goodness, eternity, or duration are great, encompassing all extremes of being. original: "ambientes omnes extremitates essendi"; this implies that Greatness provides the "scale" or reach for all other qualities. Greatness is a general principle in two ways: substantially and accidentally. Substantially, it is a general principle so that a thing may be what it is; for if it were not a substantial principle, it would not be what it is, nor would goodness, eternity, or duration, power, etc., be great. They are great substantially because they could not exist in greatness—in which they are sustained—unless the substance itself could be substantially great. Therefore, greatness is a substantial principle so that a thing is what it is, and that it can be sufficient in itself regarding the rest of the substance, and so that something can be a substantial principle because the substance is substantially great. Thus, by reason of substantial greatness, one substance generates another substance and performs other great substantial operations.

Greatness exists in an accidental substance just as goodness (which is an accident) is great by reason of greatness; thus, greatness is good accidentally by reason of goodness. Through this accidental greatness, certain principles are situated within others and "clothed" in greatness; under these conditions, the substance performs great accidental deeds that are good, durable, and so on. This same thing that we have said concerning greatness by reason of substantiality and accidentality follows for the other principles of substance. Furthermore, the intention behind placing Greatness in this art is so that specific greatnesses—which are sought out and diffused among the other principles of substance—may be understood through it and within it by the grace of greatness.