As a matter of fact, Soul is different from Nature which though unstable, still appears as stable. As a blade of reed is different from its outer cover, so is Soul different from Nature.
अन्यः स पुरुषोऽव्यक्तस्त्वध्रुवो ध्रुवसंज्ञकः। यथा मुञ्ज इषीकाणां तथैवैतद्धि जायते॥