1.		Intense heat = pain.
2.		For every x, if x cannot perceive, then x cannot have pain.
3.		Material substances cannot perceive.
4.		Material substances cannot have pain. (2,3)
5.		Material substances cannot have intense heat. (4,1)
6.		An external object is a material substance.
7.		External objects cannot have intense heat. (5,6)

Premises in the text:

1. "But is not the most vehement and intense degree of heat a very great pain? / No one can deny it." (P 164a)

2. "And is any unperceiving thing capable of pain or pleasure? / No, certainly." (P 164a)

3. "Is your material substance a senseless being or a being endowed with sense and perception? / It is senseless, without doubt." (P 164a)

4. "It [material substance] cannot, therefore, be the subject of pain? / By no means." (P 164a)

5. "Nor, consequently, [can material substances be the subject] of the greatest heat perceived by sense ..." (P 164a)

6. "What shall we say then of your external object: is it a material substance or no? / It is a material substance with the sensible qualities inhering in it." (P 164b)

C. "How then can a great heat exist in [an external object] ...?" (P 164b)