Verse 4.15
वस्तुसाम्ये चित्तभेदात्तयोर्विभक्तः पन्थाः ॥१५॥
vastu-sāmye citta-bhedāt tayoḥ vibhaktaḥ panthāḥ ||15||
The object being the same, perception and desire vary according to the various minds.
The object (nature or prakruti) is as real as the subject (purusha) , but though the substance of nature or object remains the same, the perceptions of it vary according to the difference in the development of each person's consciousness.
Here, consciousness is the perceiver and the object perceived becomes the object to be known. On account of rhe wheel of time, substance and qualities of nature, and consciousness as perceiver develop differently in each individual.
Though different perceivers see an object in different ways, it remains the same. For example, the same man or woman is a pleasure to a beloved or a lover and a pain to a rival. He or she may be an object of indifference to an ascetic and of no interest to a renunciate. Thus, the object is the same, the perceiver sees in the light of the interplay of the various gunas.
In asana and pranayama, owing to differences in one's constitution and frame of mind, techniques and sequences change, but not their essence. As soon as the consciousness is purified by removal of the impurity, asana and
pranayama disclose their essence. When an even balance is achieved, the essence of subject and object are revealed in their purest and truest forms.
When the yogi realizes that the perceiver in the form of consciousness is not the real perceiver but an instrument of its lord - the seer or purush - it begins to discard its fluctuations and also its outer form, ego, so as to blend into a single unvacillating mind.
This allows the single mind to merge in the seer, and the seer to shine forth in the light of the soul. This is Atma Jnana, leading to Brahma jnana
PATANJALI YOGA SUTRAS
