大乘義章 11.39

11.39

四種道義，出《阿含經》，《毘曇》、《成實》具廣分別。名字是何？一苦難行道、二苦易行道、三樂難行道、四樂易行道。此之四種，論釋不同。依如《毘曇》，人有利鈍，定有根本方便之別，以人依定故分四種。是義云何？如彼中釋「利根之人所行名易，易成就故。鈍根之人所行名難，難成就故。定中四禪是其根本，根本具支作用自在名為樂道。未來中間是其方便。方便定中支因不具，用不自在名為苦道。鈍人依於方便之定名苦難行，利人依於方便之定名苦易行。鈍人依於四根本禪名樂難行，利人依於四根本禪名樂易行。」成實法中，難易如上，苦樂約就定慧以說。彼宗之中，定名為苦，於照用中不自在故。慧名為樂，於照用中得自在故。鈍人得定名苦難行，利人得定名苦易行，鈍人得慧名樂難行，利人得慧名樂易行。四道如是。

The meaning of the four paths comes from the Āgamas, and the Abhidharma and Tattvasiddhi explain it in full detail. What are their names? The first is the painful path of difficult progress; the second, the painful path of easy progress; the third, the pleasant path of difficult progress; the fourth, the pleasant path of easy progress. Treatises explain these four differently. According to the Abhidharma, persons are divided into sharp and dull, and samādhi has the distinction of root and preparatory [stages]; because persons rely upon samādhi, four kinds are distinguished. What does this mean? As explained therein: 'The practice of a person with sharp faculties is called easy, because it is easily accomplished. The practice of a person with dull faculties is called difficult, because it is accomplished with difficulty. Among samādhis, the four dhyānas are the root [samādhis]; because the root is complete in its factors and its function is sovereign, it is called the pleasant path. The future and intermediate [dhyānas] are preparatory stages. In preparatory samādhis, factors and causes are incomplete and function lacks sovereignty, so they are called the painful path. When a dull person relies on a preparatory samādhi, it is called painful and difficult progress; when a sharp person relies on a preparatory samādhi, it is called painful and easy progress. When a dull person relies on the four root dhyānas, it is called pleasant and difficult progress; when a sharp person relies on the four root dhyānas, it is called pleasant and easy progress.' In the Tattvasiddhi doctrine, difficulty and ease are as above, while pain and pleasure are explained in terms of samādhi and prajñā. In that system, samādhi is called painful because it is not sovereign in illuminating function. Prajñā is called pleasant because it attains sovereignty in illuminating function. A dull person attaining samādhi is called painful and difficult progress; a sharp person attaining samādhi is called painful and easy progress; a dull person attaining prajñā is called pleasant and difficult progress; a sharp person attaining prajñā is called pleasant and easy progress. Such are the four paths.