천태종에서 법화경 이전의 절반을 적문 (迹門), 그 이후의 절반을 (本門)이라하고, (迹門)의 부처, 곧 보리수 아래에서 성도 (成道)하신 석가모니 부처님께서 법화경 이전에 말씀하신 삼승교 (三乘敎)는 방편교 (方便敎)라 하고, 법화경만을 일승진실교 (一乘眞實敎)라 하여 이를 열어 나타내시어 들어가게 함을 말함. 회삼귀일 (會三歸一) 참조

The expedient teaching or gate as a means of revealing the true teaching: It is the doctrine of the Tientai Sect that the teachings prior to the Lotus Sutra are the expedient teachings to open the way to the ultimate teaching of the Lotus Sutra, the true teaching of the One-vehicle, or the Buddha-vehicle. In other words, all the Buddha's teaching prior to the Lotus Sutra, which is called the teachings of Three-vehicles, are the expedient teachings leading to the true teaching of the One-vehicle. Cf. (Hoisam Gwiil) Threefold- vehicles returns to the One-vehicle.