If two utterances contradict one another, then they must be either both general, or both particular, or one general and the other particular, or each general in one respect and particular in another respect.
If they are both general, then if they can be reconciled one reconciles them, but if they cannot be reconciled one suspends judgment concerning them if their dates are unknown, but if their dates are known the earlier is abrogated by the later. Likewise if they are both particular. If one is general and the other particular, the general is particularized by the particular. If each is general in one respect and particular in another respect, then the generality of each is particularized by the particularity of the other.