What is being and what are its philosophical manifestations? If the transformations of being are the focus of our inquiry, our effort will focus on studying the Greek rational foundation of being in its various forms, deconstructing postmodern perceptions and their reversal of the Greek perception of being, and examining the new shift from solid being to fluid being at the beginning of the twenty-first century. Additionally, we will seek to understand the echoes of these new perceptions in other practical fields of knowledge.