Made his defense for spake for himself, A.V. ( ἀπολογουμένου, as Acts 26:2); saith for said, A.V.; mad for beside thyself, A.V.; thy much for much, A.V.; turn thee to madness for make thee mad, A.V.
With a loud voice. Another detail, betraying the eyewitness of the scene described. Thou art mad ( μαίνῃ); Acts 12:15; John 10:20; 1 Corinthians 14:23. Much learning ( τὰ πολλά γράμματα). So John 7:15, "How knoweth this man letters ( γράμματα)?"
is equivalent to Whence hath this man this wisdom? (Matthew 13:54). And ἀγράμματος in Acts 4:13 is "unlearned." The excited interruption by Festus shows that he was unable to accept the truths enunciated by the apostle.
The ideas of fulfilled prophecy, and of the resurrection of the dead, and of a crucified Jew giving light to the great Roman world, were" foolishness unto him," because he lacked spiritual discernment.
He thought the apostle's glowing words must be the outcome of a disordered mind. Turn thee to madness ( εἰς μανίαν περιτρέπει). The word μανία (mania) occurs only here in the New Testament. But it is the technical name in medical writers for the disease of μανία, mania, and is also common in classical writers.
The verb for "doth turn" ( περιτρέπει) is also peculiar to St. Luke, being found only in this place. It is used by Plato, but specially by medical writers, as is also the substantive formed from it, περιτροπή, spoken of the "turn" taken by a disease, and the simple verb τρέπει and τρέπεται: e.
g. ἔτρεψε γνώμην ἐς μανίην: ἐς σκυθρωππὸν ἡ μανίη τρέπεται: τοῖς μαινομένοισι ἄλλοτε μὲν ἐς ὀῥγὴν ἄλλοτε δὲ ἐς θυμηδίαν (mirth) ἡγνώμη τρέπεται, etc..