Conversation so far:
when was Thomas Aquinas born?
1225.
where was he born?
in the castle of Roccasecca.
are any family members listed?
he was born in the castle of his father.
where did he go to school?
began his early education at Monte Cassino.
who were some of his influences?
Aristotle, Averroes.
what was he like in early life?
At the age of nineteen Thomas resolved to join the recently founded Dominican Order.
what did he do with the dominican order?
Thomas came under the influence of John of St.
Julian, a Dominican preacher in Naples.
what did john do for him?
the Dominicans arranged to move Thomas to Rome, and from Rome, to Paris.
what did he do in rome and paris?
while on his journey to Rome, per Theodora's instructions, his brothers seized him as he was drinking from a spring and took him back to his parents at the castle.
what happened next?
Thomas was held prisoner for almost one year in the family castles.

Question: why was he held prisoner?
Self-contained rewrite: why was Thomas Aquinas held prisoner in the family castle after resolving to join the Dominican Order?