To overcome the ambiguity about the content of the concept of modernity, the concept should be analyzed in two stages. First, the concept of modernity denotes the renunciation of the past, the appreciation of the new, and the celebration of the idea of progress. Second, the concept of modernity implies a rationalist and universalist worldview, whose rise was coincident with Descartes’ rationalist epistemology. This paper examines both historically and philosophically the content of the concept of modernity and intends to elucidate what modernity is and why it has recently been criticized.