In 1578 Moroccan troops defeated a Portuguese army on Moroccan soil. Accounts written by Portuguese contemporaries report the defeat but omit mention of the fact that King Sebastian of Portugal was killed in the battle. Such omissions cannot simply be the result of ignorance of Sebastian' s death. Sebastian' s death is not even mentioned in the battle accounts written by two captured Portuguese officers while waiting to be ransomed from a Moroccan prison. These two officers actually shared their cells with the Portuguese soldiers who identified the king' s body to Moroccan officials. The omissions ttherefore had to have had a psychological cause: the Portuguese evidently found Sebastian' s death so humiliating that they could not bring themselves to write about it. The discussion about the two Portuguese officers advances the argument by ['providing grounds for eliminating an alternative explanation', 'supplying indirect evidence that a disputed death actually occurred', 'giving evidence supporting a general psychological principle on which the main conclusion is explicitly based', "offering grounds for doubting the reliability of historical reports that conflict with the argument's main conclusion"]