Institutio Oratoria

In the law courts past time is of most importance, since all accusations are concerned with what has actually been done, while what is being done or is likely to be done is inferred from the past. We also enquire into origins. For instance, we enquire whether a pestilence be due to the anger of heaven, the inclement weather, the pollution of the water-supply, or the noxious vapours emitted by the earth. Again, we seek for the motives of an act. For example, we enquire whether the fifty kings who sailed against Troy did so because they were bound by their oath, or were moved to do so by righteous indignation, or merely desired to gratify the sons of Atreus. There is no very great difference between these two classes of question.