We can say that while a process accompanies the decrease of free energy change within the system, it increases in surrounding for the same process, and the sum of the free energies of the system and surrounding, based on the conservation of energy must be zero. This is similar to Newton's third law of motion where two bodies that are in contact apply forces on each other, these forces that are in opposite directions would have the same magnitude. This means, we just look at the same process from two perspectives of the system and surrounding. In this regard, the total free energy of the universe is: