Paul saith for he said, A.V. and T.R.; excellent for noble, A.V.; words for the words, A.V. Most excellent ( κράτιστε). It appears to be the proper title to give the procurator (see Acts 23:1-35. 26; Acts 24:3).
St. Luke also applies it to Theophilus (Luke 1:3). In classical Greek οἱ κράτιστοι are the aristocracy. Soberness ( σωφροσύνη); sound or sober mindedness; just the opposite of the μανία of which he was accused.
See the use of σωφρονεῖν (Mark 5:15; Luke 8:35; 2 Corinthians 5:13, etc.), and of σωφρονίζειν σωφρωνισμός σώφρων, etc. So also in Plato, σωφρωσύνη is opposed to μανία.