Kaṭha Upaniṣad 91

91

ato 'nanyaprokta ātmany utpannā yeyam āgamapratipādyātmamatir naiṣā tarkeṇa svabuddhyābhyūhamātreṇāpaneyā na prāpaṇīyety arthaḥ / nāpanetavyā vā, na hātavyā / tārkiko hy anāgam ajñaḥ svabuddhiparikalpitaṃ yat kiñcid eva kalpayati / ata eva ca yeyam āgamaprabhūtā matis tārkikād anyenaivāgamābhijñenācāryeṇaiva proktā satī sujñānāya bhavati he preṣṭha priyatama / kā punaḥ sā tarkāgamyā matir ity ucyate / yāṃ tvaṃ matiṃ madvarapradānenāpaḥ prāptavān asi / satyā avitathaviṣayā dhṛtir yasya tava sa tvaṃ satyadhṛtiḥ / batāsīty anukampayann āha mṛtyur naciketasaṃ vakṣyamāṇavijñānastutaye / tvādṛk tv atulyo no 'smabhyaṃ bhūyād bhavatādbhavatvanyaḥ putraḥ śiṣyo vā praṣṭā / kīdṛk ? yādṛktvaṃ he naciketaḥ praṣṭā ///1,2.9 //

Shankara’s Commentary:
Com.—This idea of the atman knowable by the agamas and taught by a preceptor who is one with the atman is not to be attained by dint of one’s intelligent reasoning; or, it may mean, cannot be dispelled by mere intelligent reasoning; for, a logician not versed in the agamas will postulate something created by his own intelligence. Therefore alone, this idea arising from the agamas helps one, Oh dearest, to sound knowledge, only when taught by a preceptor who is not a logician and who is conversant with the agamas. What is that idea which can not be attained by reasoning is explained. That idea which you have now attained by my granting of the boon. Oh thou art fixed in truth. Death says this of Nachiketas with sympathetic favour, for the purpose of enlogising the knowledge which he was going to inculcate. May we find, Oh Nachiketas, a questioner like thee, a son or a disciple.