Space is infinite. All other five substances are eternally confined to a particular portion of the infinite space. The nature of soul is consciousness or sentiency. It expands and contracts according to the size of body it assumes in different births. It knows things, performs activities, enjoys pleasures, suffers pains, and illumines itself and other objects.
All souls are inherently or potentially equal.
The inequalities we notice in the world is due the fine karmic matter that veils the natural qualities of souls from beginningless time. The karmic matter is attracted towards and bound to the soul on account of its mental, vocal and bodily activities and dissociated from it as soon as it bears its fruit. When acts are performed with intense passions, the karmic matter obscures the quality for long and gives bitter fruits. So ultimately passions are the root-cause of misery and bondage. When passions are totally exterminated, all the bound karmic matter gets totally dissociated from the soul and ultimately the soul attains its pure state or liberation.