13.20 प्रकृतिम् matter, पुरुषम् spirit, च and, एव even, विद्धि know, अनादी beginningless, उभौ both, अपि also, विकारान् modifications, च and, गुणान् alities, च and, एव even, विद्धि know, प्रकृतिसंभवान् born of Prakriti.Commentary: Steps are necessary to reach the top floor of a building. Even so, steps are necessary to reach the summit of the knowledge of the Self. That is the reason why Lord Krishna took Arjuna to the summit of knowledge step by step. He first taught Arjuna the nature of the field, then knowledge, ignorance or nonwisdom, and ultimately the knowable. When a child is to be fed,the intelligent mother divides the food into small portions and feeds the child little by little. Even so Lord Krishna fed His spiritual child Arjuna with the spiritual food little by little.Lord Krishna says O Arjuna I will give you the same teaching in another form by the description of the Spirit and Nature.Till now the Lord expounded the knowledge of the field and the Self in accordance with the philosophy of the Upanishads. Now He explains the same knowledge in accordance with the Sankhya philosophy, but without accepting its dual nature in the form of discrimination between the Spirit and Nature.Vikaras Modifications from the MahatTattva or intellect down to the physical body the twentyfour principles of the Sankhyas. The Self within is changeless. All changes take place in Nature. Mulaprakriti (the Primordial Nature, the Unmanifested) becomes modified into Mahat, egoism, mind, the great elements and other minor modifications.Just as coolness and ice, the day and the night, are inseparable, so also matter and Spirit are inseparable. The three alities Sattva, Rajas and Tamas are born of Nature (matter). All actions proceed from the mind, the lifeforce, the senses and the physical body.According to the Sankhya philosophy, Prakriti and Purusha are not only eternal and beginningless but also independent of each other and selfcreated. According to Vedanta philosophy, Prakriti or Maya originates from Brahman and is, therefore, neither selfcreated nor independent. Isvara has Maya under His perfect control. Maya is His causal body. Maya is His illusory power.Matter and Spirit are the Natures of Isvara. Know that these two are beginningless. That which has no beginning is Anadi. As Isvara is eternal, His two Natures also should be eternal. (This is according to the Sankhyas.)Isvara possesses these two Natures (superior and inferior) by which He causes the creation, preservation and destruction of the universe. Therefore He has the Lordship and rules over the universe. The two Natures have no beginning. Therefore they are the cause of Samsara.The inferior Nature (Apara Prakriti) which consists of the eightfold division of Nature referred to in chapter VII, verse 4, is the Prakriti of chapter XIII, verse 19. The superior Nature (Para Prakriti) referred to in chapter VII, verse 5, is the Purusha of chapter XIII, verse 19. Purusha here means Jiva (the individual soul).Even a child smiles and experiences exhilaration, grief, fear, anger, pleasure and pain. Who taught it The impressions of the virtuous and vicious actions of this birth cannot be the cause of these. The impressions of the previous birth alone are the cause of all these. They (the impressions) must have a support. From this we can clearly infer the existence of the individual soul in the previous birth and that the individual soul is beginningless. If you do not accept that the individual soul is beginningless, the two defects of Kritanasa (nonfruition of actions performed) and Akritabhyagama (causeless effect) will creep in. Pleasure and pain which are the fruits of virtuous and vicious actions done previously will pass away without being experienced. This is the defect of Kritanasa. So also, one will have to enjoy pleasure and pain, the fruits of good and bad actions which were not done by him previously. This is the defect of Akritabhyagama. In order to get rid of these two defects we will have to accept that the individual soul is beginningless. The scriptures,also emphatically declare that the soul is beginningless.