Muṇḍaka Upaniṣad · 3.1.6
यस्तु विज्ञानवान् भवति युक्तेन मनसा सदा । तस्येन्द्रियाणि वश्यानि सधुश्व इव सारथेः
yas tu vijñānavān bhavati yuktena manasā sadā | tasya indriyāṇi vaśyāni sadhuśva iva sāratheḥ
But whoever is endowed with discrimination, with mind ever controlled — his senses are governable, as good horses of the charioteer.
The contrast: the discriminating attains inner control.
Vijñānavān — endowed with discrimination. With viveka that distinguishes the eternal from the temporal.
Yuktena manasā — with controlled, yoked mind. United with the higher, disciplined.
Sadā — always. Not occasionally but as a mode of being.
Vaśyāni — governable, subject. The senses respond to conscious direction.
Sadhuśva iva — as good horses. Well-trained steeds that obey the charioteer.
The difference lies in practice: the discriminating continuously works on self-control, not as restriction but as freedom. The senses are not enemies but instruments that, well directed, serve the higher purpose.
The journey of the well-driven chariot reaches the goal; that of the runaway chariot, the precipice.