因明入正理論疏 3.157

3.157

問：「古立有多，今何立二？」答：「《理門論》云：『由此能了自、共相故，非離此二別有所量，為了知彼更立餘量。』故依二相，唯立二量。」

Question: 'Ancient masters established many; why are only two established now?'
Answer: 'The Nyāyamukha says: "Because by these two one understands the particular characteristic (svalakṣaṇa) and universal characteristic (sāmānyalakṣaṇa); apart from these two there is no other object of cognition (prameya) such that another pramāṇa should be established to know it." Therefore, relying on the two characteristics, only two pramāṇas are established.'