In ancient Greece, court witnesses were not cross examined and the jury, selected from the citizenry, received no guidance on points of law; thus, it was extremely important for litigants to make a good impression on the jurors.
Evidence
It was extremely important for litigants to make a good impression on the jurors.
Conclusion
Courtroom oratory by litigants is a good source of data on the common conceptions of morality held by the citizens of ancient Greece.
Evaluate
The argument assumes that impressing the jurors was best accomplished by reflecting the common conceptions of morality held by the citizenry.