Kaṭha Upaniṣad 82

82

avidyāyām antare vartamānāḥ svayaṃ dhīrāḥ paṇḍitaṃ manyamānāḥ /
dandramyamāṇāḥ pariyanti mūḍhā andhenaiva nīyamānā yathāndhāḥ ///1,2.5 //

5. Living in the middle of ignorance and regarding themselves as intelligent and learned, the ignorant go round and round, in many crooked ways, like the blind led by the blind.