Whatever we see, think, contemplate and do the result of which self-expression is called the causal body that means, that gross and subtle body are the "cause" of the causal body from the true nature of the Self or Atman and from the experience and discriminating discernment the causal body is always free it can be experienced even in deep sleep state due to ignorance in waking and in dream state it can also be called the bliss sheath (anandamaya kosha) 