b. The Second Way: from the Order of Substance to Accidents

82. From the second way I argue as follows: substance is naturally prior to every accident, according to the Philosopher Metaphysics 7.1.1028a10-b2. And his intention concerns the substance that is one of the dividers of being [sc. into categories], so that to expound ‘substance’ there of God or the first substance is not relevant to his intention. For he proves that substance is first in the way he proves that substance is of the number of the dividers of being - that it is prior to every accident, namely such that, in order to determine everything that divides being, it suffices to determine substance as what is first, because the knowledge of accidents is had from the fact they are attributed to substance; but this is only to the purpose about substance in its whole ordering; for nothing posterior to this ordering can be the formal reason whereby something is in that ordering. Therefore, from the idea of the priority of substance universally, as it is something common, sufficient determination is made about the ordering that is the ordering of primary substance, to which this natural priority to any accident belongs; so being a ‘this’ naturally prior to its determination by any accident belongs to primary substance in its idea.

83. And the consequence can be confirmed, because when something is prior to something else, the maximally first of that something is prior to the something else; but the maximally first in substance in general is primary substance; therefore primary substance is simply prior to every accident, and so it is first a ‘this’ before it is determined in any way by anything else.

84. Here it is said [by Godfrey of Fontaines] that although primary substance is prior to quantity in existing yet not in dividing - just as also secondary substance is prior in entity but not in divisibility.

85. On the contrary:

This response destroys itself, because if primary substance is naturally prior to quantity in existing, and if primary substance cannot be understood in its existence unless it be understood as it is a ‘this’, then it is not prior in existing unless it is prior as a ‘this’; therefore it is not a ‘this’ by quantity.

86. Further, form is prior simply to the composite, according to the Philosopher’s proof Metaphysics 7.2.1029a507. Therefore if quantity is the form of primary substance insofar as it is primary substance, then quantity will be simply prior in being to primary substance - because if quantity is not the form in being, then it is not the form in dividing either, or in the unity that belongs to primary substance insofar as primary substance is such a being (for any entity is followed by its proper unity, which unity does not have any other proper cause of itself than the cause of entity).

87. Further, substance, in the way that it is the subject for every accident, is naturally prior to every accident. For, insofar as it is the subject, it is proved to be prior in definition to every accident, for it is by way of addition thus posited in the order of any definition; but as it is the subject it is ‘this substance’, because, according to the Philosopher Physics 2.3.195b25-26 and Metaphysics 1.1.981a16-19, singulars are causes of singulars (in any genus of cause), so a singular subject is cause of a singular accident. And there is an especial confirmation of this as to an accident in an accident, because that is present first in a singular, according to the Philosopher Metaphysics 5.9.1017b35-1018a3 , ch. ‘On the Same’.

88. Further, everything that is prior in nature to something else is prior to it in duration, in the way that - as far as concerns it of itself - there is in it no repugnance of contradiction in its being able to be prior in duration to its posterior; for priority of nature universally includes in the prior thing the ability, without contradiction, to exist in the absence of its posterior, from Metaphysics 5.11.1019a2-4 ch. ‘On the Prior’. Therefore any substance (as far as concerns itself) can, without contradiction, exist prior in duration to any accident, and thus prior to quantity.