Bhagavad Gita 7.27इच्छाद्वेषसमुत्थेन द्वन्द्वमोहेन भारत।सर्वभूतानि संमोहं सर्गे यान्ति परन्तप ॥

Where there is pleasure there is Raga or attachment where there is pain there is Dvesha or aversion. There is the instinct in man to preserve his body. Man wishes to attain those objects which help the preservation of the body. He wishes to get rid of those objects which give pain to the body and the mind. On account of delusion caused by the pairs of opposites, desire and aversion spring up and man cannot get the knowledge of the things as they are, even of this external universe of senseexperience and it needs no saying that in a man whose intellect is overwhelmed by desire and aversion there cannot arise the transcendental knowledge of the innermost Self.Raga (attraction) and Dvesha (repulsion), pleasure and pain, heat and cold, happiness and misery, joy and sorrow, success and failure, censure and priase, honour and dishonour are the Dvandvas or the pairs of opposites. Desire and aversion (or attraction and repulsion) induce delusion in all beings and serve as obstacles to the dawn of the knowledge of the Self.He whose intellect is obscured by the delusion caused by the pairs of opposites is not able to realise I am the Self. Therefore he does not adore Me as the Self.He who is a victim of RagaDvesha loses the power of discrimination. He wishes that pleasant objects should last for ever and that disagreeable or unpleasant objects should disappear immediately