Srimad-Bhagavatam: Canto 11 - Chapter 1 - Verse 9-10

Sanskrit:

श्रीभगवानुवाचअहमित्यन्यथाबुद्धि: प्रमत्तस्य यथा हृदि ।उत्सर्पति रजो घोरं ततो वैकारिकं मन: ॥ ९ ॥रजोयुक्तस्य मनस: सङ्कल्प: सविकल्पक: ।तत: कामो गुणध्यानाद् दु:सह: स्याद्धि दुर्मते: ॥ १० ॥

ITRANS:

śrī-bhagavān uvācaaham ity anyathā-buddhiḥpramattasya yathā hṛdiutsarpati rajo ghoraṁtato vaikārikaṁ manaḥ

Translation:

The Supreme Personality of Godhead said: My dear Uddhava, a person bereft of intelligence first falsely identifies himself with the material body and mind, and when such false knowledge arises within one’s consciousness, material passion, the cause of great suffering, pervades the mind, which by nature is situated in goodness. Then the mind, contaminated by passion, becomes absorbed in making and changing many plans for material advancement. Thus, by constantly thinking of the modes of material nature, a foolish person is afflicted with unbearable material desires.

Purport:

Those who are trying to enjoy material sense gratification are not actually intelligent, although they consider themselves most intelligent. Although such foolish persons themselves criticize the miseries of material life in innumerable books, songs, newspapers, television programs, civic committees, etc., they cannot desist from material life for a single moment. The process by which one is helplessly bound in illusion is clearly described here. A materialistic person is always thinking, “Oh, what a beautiful house. I wish we could buy it” or “What a beautiful woman. I wish I could touch her” or “What a powerful position. I wish I could occupy it” and so on. The words saṅkalpaḥ sa-vikalpakaḥ indicate that a materialist is always making new plans or modifying his old plans to increase his material enjoyment, although in his saner moments he admits that material life is full of suffering. The mind is created from the mode of goodness, as described in Sāṅkhya philosophy, and the natural, peaceful situation of the mind is pure love of Kṛṣṇa, in which there is no mental disturbance, disappointment or confusion. Artificially, the mind is dragged down to a lower platform in passion or ignorance, and thus one is never satisfied.