The entire content of this mail is from Shri V N Gopala Desikan's Srimad Bhagavad Gita, published by Vishishtadvaita Research Centre, Chennai and The Bhagavad Gita by Swami Chidbhavananda published by Ramakrishna Mission
The Three Gunas Give Impetus to Karma - 18-40
1 Gita Sloka Every Day - Chapter 18 - Moksha Sanyasa Yoga - Sloka 21
Pruthaktvena tu yat gyanam nana bhavan pruthak vidhan I
Vetti sarveshu bhuteshu tat gyanam viddhi rajasam II sloka 21
पृथक्त्वेन तु यत् ज्ञानं नाना भावान पृथक् विधान I
वेत्ति सर्वेषु भूतेषु तत् ज्ञानं विद्धि राजसं II श्लोक 21
But that knowledge by which one sees in all beings manifold entities of different kinds as varying from one another - know that knowledge as rajasika.
The rajasika knowledge holds that there are atmas of varying traits residing in bodies of various types and grades of evolution. The atman itself has to undergo evolution as the body does, is the view entertained by this school of thought.
Gold ore maybe procured from different continents and they may all have different kinds of dross pertaining to the nature of the earth. While there is difference in the dross, pure gold is the same, independent of the sediment and the soil. Similarly the Atma seem different from one another because of the limited adjuncts - Upadhis. It is even believed that Atmas belong to different species, castes, colours and nationalities. Attaching importance to these upadhis is the way of the Rajasika knowledge. But these limiting adjuncts are born of ignorance. When they are all eliminated, Pure consciousness alone remains. The underlying unity are not cognised by the Rajasika knowledge. It sees nothing but diversity.