as early as the fifteenth century, the popularity of the theory of rebus sic stantibus had begun to wane, largely because of protests from burgeoning commercial interests against the climate of transactional insecurity produced by the theory's widespread application. By the end of the eighteenth century, pacta sunt servanda reigned supreme, and the theory of rebus sic stantibus had been relegated to the doctrinal scrap heap. Contributing to its demise were the rise of scientific positivism, and the increasing emphasis on individual autonomy and liberty of contract.