Presenting his view of life as optimism triumphant, Dr. Ken Merz, Sr., reflects on the limits of life, the limits of the physical universe and the role of humans in that universe. He explains various laws of science in a clear and accessible style while reviewing aspects of physical reality, aspects of biological reality and definitions of scientific reality. Discussing mankind's ongoing search for truth, he examines the distinction between believing and knowing. The book's themes include time and change, with a consideration of the work of Darwin, Mendel, and Watson and Crick. Explaining the basics of the double helix of DNA and the micro evolution of life, Dr. Merz ponders individualism and evolution, and makes a plea for humans to wield their power over life responsibly. Recent events forcefully show that humans live on a limited planet and themselves have limited abilities. Limits face us from every direction. The Earth has a limited surface with limited arable and to farm, oxygen to breathe, water to drink, atoms to use and oil to burn. We are pressing against Earth's resources with unachievable demands. Humans have limits in their sensory ability, memory, perception of truth and endurance in the face of unending change. Science is limited to 92 elements and phenomena that are observable. Economics is limited to raising prices or seeking alternates. In a universe of unending change, existence itself is limited. Malthus, Toynbee, Tainter, Meadows, Diamond and many others have warned us of looming limits that would someday engulf our civilization. Nevertheless, we have continued to exploit resources wastefully, pollute the environment and cause extinctions. Man has searched for millennia but only since the time of Copernicus (1473–1543), Galileo (1564–1642), and Newton (1642–1727) has a reasonably useful procedure been found for finding truth: the scientific method of investigation. That method is the present source of humanity's ascendancy over the Earth and its creatures. The book explains the scientific method in terms of logic as well as the day to day activities of scientists. The method is the basis of higher living standards, improved health and longevity, and population growth. These are now diffusing into the countries of the third world, increasing the pressure on natural resources. We have learned from science that living creatures, including humans, were created by and are controlled by DNA — the double helix of deoxyribonucleic acid — which has been evolving for at least 3.5 billion years. DNA controls behavior as well as our physical bodies. If, as the only conscious and rational creature, we are to accept and fulfill the role as Natural Selector of life on Earth, we must somehow achieve a collective ethical nature commensurate with the task. We cannot wait hundreds of centuries for DNA to do it; there is no time. We must solve the problems of Earth and human survival with what we now have. Our only trustworthy hope is to follow the methods of science, listening carefully along the way. The Earth is now our home and responsibility; we must finally heed Buddha's injunction of 2500 years ago: The self is master of the self: for who else could be the master?