expatiate

professorial, prosecutorial
his words ring out with authority
despite their extemporaneity
as he explicates and expatiates
and dictates in spates
of laborious lectures
in which he highly rates
his own opinion
until someone
challenges him
then rather than defend
a stance
he happened upon
by chance
he blames the other
for disagreeing
he blames the light
for showing the holes
he blames and shames
and never names
himself