What is the 'causal body' and what is the only way to get rid of it?

The 'causal body,' referred to as 'karana' in Chapter 50, is the most fundamental layer of the individual soul's embodiment. It is also known as the 'Unmanifest' (Avyakruta). The text explains that this body is directly caused by 'the ignorance of the Soul'—a state of pure, foundational nescience about one's true identity. It is described as being with the reflection of consciousness but rooted in ignorance. According to the guidance in Chapter 50, there is a singular method for its removal. The text states unequivocally that 'Only the knowledge of the unity of Brahman and the Soul—by that alone is the removal of this body.' No other path or practice will suffice; only this ultimate realization can dispel the ignorance that forms the causal body, leading toward liberation.