Lord Krishna clarified that there are two things in the world: the Soul and the non-soul (matter). Now if people were to think of matter as being the Soul, then what would become of the Soul? If there is only wheat everywhere, then there is no need to pick and sort out wheat from the tiny stones we generally find mixed with wheat grains. However, when the two are mixed together but we are led to believe that there is only wheat (not a mixture of the two), why then would one attempt to separate the two?