Source: pp 65-66, The Art of the Advocate (1993) by Richard Du Cann QC.
No clear principle can be formulated. It is safe to say only the advocate must at all cost avoid the once indulged in by Treasury at the Old Bailey who finished his with these words:
[1.] I have set the stage you Members of the Jury. The scenery is in place. Let me ring up the curtain and the play begin.
Defending counsel, in an aside which rang the court, asked him:
[2.] And have your actors learned their lines?
I can infer that 2 is intended to ridicule the hyperbole of 1 (in metaphorising the trial court as a drama in a theatre). But why is 2 apt and effective?
Whom does 'actors' allegorise?
What does 'lines' allegorise?