The article revisits the originality of Hobbes's concept of happiness on the basis of Hobbes's two accounts found respectively in Thomas White's De Mundo Examined and Leviathan. It is argued that Hobbes's claim that happiness consists in the unhindered advance from one acquired good to another ought to be understood against the background of Hobbes's theory of sensation and the imagination, on the one hand, and Hobbes's doctrine of conatus, on the other. It is further claimed that the account of happiness in White's De Mundo differs from that in Leviathan. In the former work, happiness is defined not as the mere progression from one good to another but as the joy/mental pleasure derived from the awareness of one's unhindered advance. The traditional claim that Hobbes is an ethical subjectivist is examined in connection with Hobbes's view of the subjectivity of happiness and the rejection of the summum bonum. Lastly, Hobbes's distinction between worldly and everlasting happiness is discussed.