俱舍論疏 26.104

26.104

論「不爾他心智至能自緣失」，反難釋也。若不如上所釋，不知所緣及能緣行相，即有二失。若知他心所緣，即有他心智緣色等境，及自知過。若知他心能緣行相者，即自知失，自心是彼他心能緣行相故。故《婆沙》九十九云「又他心智但緣他心不緣他心所緣行相。若緣他心所緣行相，應緣自心，非他心智，自心是彼所緣及能緣行相故。」

On the Śāstra's statement: "Otherwise, the knowledge of another's mind […] the fault of apprehending itself": this explains by an ad absurdum challenge. If it were not as explained above, not knowing the object and the apprehending cognitive mode, there would be two faults. If it knew the object of another's mind, there would be the fault that the knowledge of another's mind takes objects such as visible forms, and that it knows itself. If it knew the apprehending cognitive mode of another's mind, it would incur the fault of knowing itself, because one's own mind is that other mind's apprehending cognitive mode. Hence Vibhāṣā fascicle 99 states: "Furthermore, the knowledge of another's mind only takes another's mind as its object and does not take the cognitive mode of that other mind's object as its object. If it took the cognitive mode of that other mind's object as its object, it would take its own mind as an object, which is not the knowledge of another's mind, because its own mind is that object and the apprehending cognitive mode."