1–3 These lines are Marlowe’s challenge to the stage conventions of the time, proclaiming a new kind of verse, unrhymed and heroic, to replace the doggerel rhymes and jog-trot rhythms of the popular drama of the previous years. He rejects the whims and tricks (‘conceits’) of clowns and jesters, preferring a more elevated and ‘stately’ theme.

1 mother wits those who possess ‘mother wit’, i.e. native or natural wit (O.E.D.; here used contemptuously)