This is an excerpt from The Four Imams by Muhammad Zahra regarding Imam Hanifa's intelligence and skill in debating.
CONVERSATION WITH ATHEISTS
Abu Hanifa was an observant man, and from the time of his youth, was fond of debate and argument in the quest for knowledge. He used to go to Basra, the home of Islamic sects, and debate with their leaders and argue with them about their views.
It is related that once he debated with the Dahrites (materialist atheists) and in order to call their attention to the neccessity of a Creator of the universe, he asked them, "What do you say about someone who tells you, "I saw a laden ship full of goods and cargo which it bore across the deap seas through crashing waves and veering winds, travelling straight through them without any sailor to direct and guide it or helmsman to move it? Would that be logically possible?""No," they said, "this is not logically possible and cannot be imagined." Abu Hanifa said,"Glory be to God! If the existence of a ship on an even keel without a mariner or helmsman is not concievable, how can it be possible for this world with all its different circumstances, changing matters and actions, and vast expanse to be without a Maker, Preserver and Originator?"