X

As air, though one, having entered the world, becomes various according to what it enters, so does the Atman within all living beings, though one, become various according to what it enters. It also exists outside.

By using these similies of fire and air, the teacher tries to show Nachiketas the subtle quality of the great Self, who, although one and formless like air and fire, yet assumes different shapes according to the form in which It dwells. But, being all-pervading and unlimited, It cannot be confined to these forms; therefore it is said that It also exists outside all forms.