यद्वै तन्न मनुते मन्वानो वै तन्न मनुते ।न हि मन्तुर्मतेर्विपरिलोपो विद्यतेऽविनाशित्वात् ।न तु तद्द्वितीयमस्ति ततोऽन्यद्विभक्तं यन्मन्वीत ॥बृह. ४,३.२८ ॥
In plain words
And when it is said that he does not think, he is thinking though he does not think; for there is no cessation of the thinking of the thinker, since he is indestructible. But there is no second thing, separate from him, of which he could think.