Society is shaped by the process of choice. Choice is a fundamental process of human existence, for in daily life and in the course of our lifetimes the way in which we exist as people is founded on the choices we make for ourselves and also on those made by others. Choice is an expression of human individuality, for through the choices we make we express our beliefs, values and personal priorities. Choice, though, is an interactive process. Our every choice impacts on other people, and their choices impact upon us. The choices an individual, a group or an organisation make result in changes to the world they occupy, and in so doing change the environment of choice for every other individual, group or organisation. The social, economic and cultural environment within which we all operate is the product of choices throughout human history and they constrain and shape the choices open to individuals at any particular moment. Although we are the product of our own choices, many of those choices will be highly constrained by these external environmental structures that define the way in which we live in society.