"Matsyanyaya" is an ancient Indian word that connotes roughly "Law of Fishes." "Law of Fishes" means a System of Fishes in which Big-Fishes kill Small-Fishes at will for Food or for Pleasure. It is a Struggle for Existence for the Small Fish which is less in Power to the Big Fish. It has to survive with Policy. Then there is the Fisherman who is apparently ''outside'' the System, but in fact, very much part of it. The Matsyanyaya Imagery is actually an Imagery of Power and is a part of our Existential Reality. In this book I will show how Mahabharata exemplifies that System through the Kuru-Pandava political war. The Pandavas are the Small Fish, and it is Krishna who take their side to suggest and implement Policy that ultimate enable the Pandavas to defeat the Big Fish Kauravas. However, there is more to the Imagery. It is also a Spiritual Imagery. Krishna shows how one needs to be "Fisherman" in both Internal-External Reality to win in the battle of Survival. That is Vyasa''s central message in Mahabharata.