Regarding my enemies assertion that it is hypocritical to use SGI source materials, Nichiren made use of the commentaries of those he considered to be slanderers of the Dharma, for example, the following passage from the Learned Doctor Shan-wu-wei in the Opening of the Eyes:
"The characters Myoho-renge-kyo are Chinese. In India, the Lotus Sutra is called Saddharma-pundarika-sutra. The following is the mantra concerning the heart of the Lotus Sutra composed by the Tripitaka Master Shan-wu-wei: namah samanta-buddhanam om a a am ah sarva-buddha-jna-sakshebhyah gagana-sambhavalakshani saddharma-pundarika-sutra jah hum bam hoh vajrarakshaman hum svaha Hail to all the Buddhas! Three- bodied Thus Come Ones! Open the door to, show me, cause me to awaken to, and to enter into the wisdom and insight of all the Buddhas. You who are like space and who have freed yourself from form! Oh, Sutra of the White Lotus of the Correct Law! Cause me to enter into, to be everywhere within, to dwell in, and to rejoice in you. Oh, Adamantine Protector! Oh, empty, aspect-free, and desire-free sutra!
This mantra, which expresses the heart of the Lotus Sutra, was found in the iron tower in southern India. In this mantra, saddharma means “correct Law.” Sad means correct. Correct is the same as myo [wonderful]; myo is the same as correct. Hence the Lotus Sutra of the Correct Law and the Lotus Sutra of the Wonderful Law. And when the two characters for namu are prefixed to Myoho-renge-kyo, or the Lotus Sutra of the Wonderful Law, we have the formula Namu-myoho-renge-kyo."
The use of other's source materials can be likened to a master judaoka using his opponent's strength against him.