To understand what Hobbes mean by happiness we must consider his idea of human nature. His main statements are.
Nature created people equal. Nature created people equal in according with their physical and intellectual faculties.
However sometime we can see that one person is stronger physically or more intellectual than another.
But when it is viewed together there are no essential differences between humans, what might one get the better of anther. Because if somebody has more physical strength than anther has enough craft to kill more strong man on his own or with assistance people who have same danger.
Equality generates mutual suspicion. Through equality of the capabilities the equality of the hopes to achieve goal arises. That is why when two persons want the same item which they can not possess together they become enemies.
So when they are achieving that goal they try to destroy or to conquer each other. Thus if man gripes, sows has some decent estate and can arrange attack on his own only he should wait for people who will come together to bereave his property and to imprison or to kill him. But the
assailant run same risk.
The war is through mutual suspicion. On account of such mutual suspicion there is the best way to protect his life and property is keeping in check all whom possible. Methods which are used for self-preservation usually are considered acceptable. But there is a number of people who for the sake of delight to contemplate his power while conquering continue it.
That is why if one wants to protect his existence he must to improve his power.
Hence Hobbes made conclusion that happiness is not in soul serenity.
There is no finis ultimus (final goal) or summum bonum(highest good) what are described by ancient philosophies.
Because humane who doesn t have any wishes unable to live as well as humane who doesn t have any capability to feel and to express. Thus happiness is constant success, happiness is in constant movement of the wish from one subject to another because the previous success is the step for next.
So in according with abovementioned idea of humane nature Hobbes come to conclusion the course of happiness is power.