 In chapter V of the Regulae, Heytesbury considers the limits of capacities, and he applies the limit-concept to the bounding of the ranges of variables and aggregates. All capacities are sorted as active or passive. An active capacity (force) is measured against the passive capacity (resistance) which it can overcome. If an active capacity can overcome some resistance, it can overcome less. For example, if Socrates can lift one hundred pounds, he can lift fifty pounds. Conversely, if a passive capacity can be affected by less, it can be affected by greater. For example, if Socrates can see a grain of millet from the distance of a mile, he will be able to see the Church at the same distance. The boundaries of capacities are of two kinds: an intrinsic boundary (when an element is a member of the sequence of elements it bounds: maximum quod sic, minimum quod sic) and an extrinsic boundary (when an element which serves as a boundary stands outside the range of elements which it bounds: maximum quod non, minimum quod non). From the definitions of active and passive capacities, it follows that the boundary of an active capacity must be assigned either by the affirmation of the maximum (maximum quod sic) or by the negation of the minimum (minimum quod non); the boundary of a passive capacity is assigned either by the affirmation of the minimum (minimum quod sic) or by the negation of the maximum (maximum quod non).