Contrary to the conventional wisdom held by many in much of human history, in this book Peter Baofu here proposes what he calls the perspectival theory of space-time. According to this theory, there are multiple perspectives of space and time in society, culture, the mind, and nature, all of which are subject to the regression-progression principle in existential dialectics. These perspectives exist in society, culture, the mind, and nature with good reasons, being subject to the symmetry-asymmetry principle in existential dialectics and with some being more successful and hegemonic (dominant) than others. Furthermore and more importantly in the long haul, space and time as humans have known them will end and will eventually be altered by post-humans in different forms, be they here in this universe or in multiverses, subject to the change-constancy principle in existential dialectics.