Dasya, sakhya, vatsalya and srngara are the transcendental modes of loving service to the Lord. Santa-rasa, or the neutral stage, is not mentioned in this verse because although in santa-rasa one considers the Absolute Truth the sublime great, one does not go beyond that conception. Santa-rasa is a very grand idea for materialistic philosophers, but such idealistic appreciation is only the beginning; it is the lowest among the relationships in the spiritual world. Santa-rasa is not given much importance because as soon as there is a slight understanding between the knower and the known, active loving transcendental reciprocations and exchanges begin. Dasya-rasa is the basic relationship between Krsna and His devotees; therefore this verse considers dasya the first stage of transcendental devotional service.