ज्योति: सर्वस्य लोकस्य विपुल प्रतिपद्यते । न त्वेव गमन॑ राजन् हेतुतो गमनं तथा । अग्राह्मुमनिबद्धं च वाचा सम्परिवर्जयेत्
jyotiḥ sarvasya lokasya vipula pratipadyate | na tveva gamanaṁ rājan hetuto gamanaṁ tathā | agrāhyam anibaddhaṁ ca vācā samparivarjayet |
Bhishma said: “When the play of mere reasoning is exhausted, abundant true understanding is attained; that knowledge becomes the finest light for the whole world. But, O King, what is reached only by argument is not, in that same sense, a reliable ‘going’ to truth. Therefore one should avoid, even in speech, what is not fit to be accepted and what is ungrounded—especially any claim not established by authoritative teaching.”
भीष्म उवाच
Bhīṣma teaches that mere logical argument (hetu/tarka) is not sufficient as a final authority for truth; genuine knowledge is a ‘light’ for the world and should be grounded in reliable pramāṇa—here, especially what is established by Vedic/scriptural authority—while unfounded or inadmissible claims should be avoided even in speech.
In the Anuśāsana Parva, Bhīṣma, lying on the bed of arrows, continues instructing King Yudhiṣṭhira on dharma. In this verse he cautions the king against treating bare reasoning as definitive knowledge and urges adherence to authoritative, well-established teachings.