William James (1842-1910) had been discussing the idea of the 'meliorism' since he started to study philosophy. According to this idea, we humans can intervene in and change the processes or events of the world through our free-wills and actions produced by them, and thereby can improve it. The 'meliorism' must not be considered only as a result of James' 'optimistic' temperament. It supposes his several philosophical notions which are closely intertwined with each other, and is necessarily derived from them. The purpose of this study is to elucidate what the conceptions of 'free-will' and 'novelty' mean in James' thought in order to contribute to the understanding of the 'meliorism.' These two notions are very important components of it, but it doesn't seem that their importance have been recognized by researchers of James' philosophy. First, James defends the idea of 'free-will' by criticizing the determinism, which denies the existence of freedom and insists that what happens in the world is in advance determined by the absolute God or the law of nature. He says that the determinism commits some errors or contradicts itself, and therefore it is an untenable position. After that, James shows what the 'novelty' of the world is and how it is produced. We try to resolve these problems by associating this idea with James' notions of 'pure experience', the 'discontinuity-theory' and 'external relations.' In doing so, we can arrive at the conclusion that 'novelty' is the real creation of the world and that 'pure experience' is the source from which 'novelty' comes.