The history of humanity is a continuous process of moving from the realm of necessity to the realm of freedom. This historical process will never come to an end. In class-based societies, class struggle will persist; in classless societies, the struggle between the new and the old, between what is correct and what is wrong, will likewise never cease. Within the spheres of productive labor and scientific experimentation, both human society and the natural world are constantly evolving and will never remain static at any given level. Consequently, humankind must continually draw lessons from experience, make new discoveries, invent, create, and advance. Views that advocate stagnation, pessimism, inaction, or complacency are all erroneous. They are erroneous because they contradict the historical facts of human social development over roughly one million years, as well as the historical facts about the natural world as revealed by our knowledge to date—such as those found in the histories of celestial bodies, the Earth, living organisms, and other branches of natural science.