Causal Vehicles

The first three vehicles together represent the non-tantric vehicles, here referred to as "causal vehicles focused on characteristics" (mtshan nyid rgyu yi theg pa). "Causal" indicates that these vehicles focus on the cause of Buddhahood in practice, in contrast to tantra's focus on the actual fruit of Buddhahood in contemplation and ideology. There are various versions of the nine-vehicle scheme in Nyingma sources, and early ones begin with a non-Buddhist vehicle often called that of "gods and men" (lha mi).