‘What, Nāgasena, is the distinguishing characteristic of perception (Viññāṇa)?’

‘Recognition, great king.’

‘Give me an illustration.’

‘It is like the case of the guardian of a city who, when seated at the cross roads in the middle of the city, could see a man coming from the East, or the South, or the West, or the North. In the same way, O king, he knows an object which he sees with his eye, or a sound which he hears with his ear, or an odour which he smells by his nose, or a taste which he experiences with his tongue, or a touchable thing which he touches with his body, or a quality that he recognises by his mind. Thus is it, great king, that knowing is the mark of perception.’

‘Very good, Nāgasena!’