The Soul (Jīva or Ātma) is defined as a non-material, eternal spiritual entity present within any living being. The symptom of the presence of the soul within a body is consciousness. The soul continues to exist after the destruction of the body and it existed prior to the creation of the body. The material body develops, changes and produces by-products [offspring] because of the presence of the soul within. The material body deteriorates in due cause of time and when it is no longer a suitable residence for the soul it is forced to leave the body. This we call death. So where does the Soul come from?
Jīva-Tattva is the science of the Soul
Quotes from the Vedic Scriptures A Treatise On The Bondage Of The Jiva