Sri Madhva Acharya preached Dvaita Vedanta in the 13th Century A.D. This school of thought directly opposed with Sankara's Advaita Vedanta. Sri Madhva was the author of many works most important of which are Madhva Bhashya and Anu Vyakhyana both of which were written on Vedanta Sutras.
Shankara insisted on the oneness or identity of all things, so much so that in his vision of ultimate reality all "things" or separateness as such ceased to exist. In the philosophy of Acarya Madhva it is stated that there are five kinds of differences:
1. Difference between God and the individual soul.
2. Difference between God and matter.
3. Differences between individuals.
4. Differences between individuals and matter.
5. Differences between different types of matter - i.e. earth, water, fire, air, ether, mind, intelligence and false ego.