Contact, sensation, and idea

The king said: ‘Where thought (mental perception) is, Nāgasena, is there always sensation?’
‘Yes, where thought arises there is contact, and there is sensation, and there is idea, and there is conceived intention, and there is reflection; and there is investigation.’
‘Reverend Sir, what is the distinguishing characteristic of contact (Phassa)?’
‘Touch, O king.’
‘But give me an illustration.’
‘It is as when two rams are butting together, O king. The eye should be regarded as one of those two, the form (object) as the other, and the contact as the union of the two.’
‘Give me a further illustration.’
‘It is as when two cymbals are clashed together. The one is as the eye, the other as the object, and the junction of the two is like contact.’
‘Very good, Nāgasena!’