This book traces the history of life-concepts, with a focus on the vegetable souls of Aristotle, investigating how they were interpreted and eventually replaced by evolutionary biology. Philosophers have long struggled with the relationship between physics, physiology, and psychology, asking questions of organization, purpose, and agency. For two millennia, the vegetable soul, nutrition, and reproduction were commonly used to understand basic life and connect it to "higher" animal and vegetable life. Cartesian dualism and mechanism destroyed this bridge and left biology without an organizing principle until Darwin. Modern biology parallels Aristotelian vegetable life-concepts, but remains incompatible with the animal, rational, subjective, and spiritual life-concepts that developed through the centuries. Recent discoveries call for a second look at Aristotle's ideas - though not their medieval descendants. Life remains an active, chemical process whose cause, identity, and purpose is self-perpetuation.

This book provides a straightforward introduction to teleology in biology, the work it did and the work it can do. Informed by history and philosophy, it focuses on scientific concerns. Seventeenth, eighteenth, and nineteenth century biologists proposed a menagerie of biological "actors" to explain power without appealing to Aristotelian vegetable souls and final causes. Three constraints on teleology narrowed the field, selecting among the various actors as they mutated and recombined. Methodological naturalism, local adaptation, and blind chance each represent a significant philosophical advance in biology. Kant, Darwin, and the Modern Synthesis provided a new teleology, grounded in natural selection, an etiological recursion of form and function, and the details of carbon chemistry on Earth. They naturalized teleology, but they also finalized nature, shifting conceptions about the world and science. Understanding these links - historical, philosophical, and theoretical - sets the stage for new work moving forward.

This book traces the history of life-concepts, with a focus on the vegetable souls of Aristotle, investigating how they were interpreted and eventually replaced by evolutionary biology. Philosophers have long struggled with the relationship between physics, physiology, and psychology, asking questions of organization, purpose, and agency. For two millennia, the vegetable soul, nutrition, and reproduction were commonly used to understand basic life and connect it to "higher" animal and vegetable life. Cartesian dualism and mechanism destroyed this bridge and left biology without an organizing principle until Darwin. Modern biology parallels Aristotelian vegetable life-concepts, but remains incompatible with the animal, rational, subjective, and spiritual life-concepts that developed through the centuries. Recent discoveries call for a second look at Aristotle's ideas - though not their medieval descendants. Life remains an active, chemical process whose cause, identity, and purpose is self-perpetuation.

Life is a property of the universe. We may not know how it began or where else it exists, but we have come to know a great deal about how it relates to stars, planets, and the larger cosmos. In clear and compelling terms, this book shows how the emerging field of astrobiology investigates the nature of life in space. How did life begin? How common is it? Where do we fit in? These are the important questions that astrobiology seeks to answer.

A truly interdisciplinary endeavor, astrobiology looks at the evidence of astronomy, biology, physics, chemistry, and a host of other fields. A grand narrative emerges, beginning from the smallest, most common particles yet producing amazing complexity and order. Lucas Mix is a congenial guide through the depths of astrobiology, exploring how the presence of planets around other stars affects our knowledge of our own; how water, carbon, and electrons interact to form life as we know it; and how the processes of evolution and entropy act upon every living thing.

This book also reveals that our understanding and our context are deeply intertwined. It shows how much astrobiology can tell us about who we are as a planet, as a species, and as individuals.