Nothing ever begins to be, Nayam Bhootva Bhavita vana Bhooyah ! Ice when heated becomes water. Water when cooled becomes ice. Water when heated becomes vapour. So Essence or Energy is not destroyed. The Law of Conservation of Energy, expressed mathematically as Sigma ( energy after ) = Sigma ( energy before ). So Essence only undergoes a parallel transformation, into conditions which preexisted in other conditions. So every state has a posterior and an anterior state. So it is logical to assume that our states have an anterior and posterior existence ! This is the Logic behind Metempsychosis or the Law of Rebirth !