The dialogue opens with a king who has run out of opponents. Milinda, learned in the arts and sciences and delighting in debate, has silenced the teachers of his realm and asks whether anyone remains who can answer him; he is brought to Nagasena. Their first exchange sets the theme of the whole work. Asked his name, the monk replies that he is called Nagasena, but that the name is a designation only, for no person is found here. The king objects: then who wears the robe, who keeps the precepts, who could murder a monk if there is no one there. Nagasena answers with the king's own chariot. Is the pole the chariot, the axle, the wheels, the frame, the yoke.
Is the chariot something other than these parts. It is neither, the king concedes, and yet chariot is not a false word: it is a designation dependent on the parts being assembled. Just so, Nagasena concludes, the person is a designation dependent on the aggregates, and the point is sealed with a verse from the canon in which the nun Vajira says the same to Mara. From there the questions multiply: on rebirth without transmigration, answered with the flame lit from another flame and the milk that becomes curds; on why the liberated still feel bodily pain; on how a deed long past can bear fruit. The form is catechism sharpened into philosophy, and the similes have travelled far beyond Buddhism.