One of the earliest aims and accomplishments of modern science was
the mathematical expression of the laws governing the behavior of physical
systems. More recently, scientists have sought and found underlying rules
of behavior in economic, military, social, and biological processes. Once
a law of causality has been determined-or, as is more often the case,
approximated-for a given system, it is often seen that the behavior of the
system can be influenced by the choice of certain parameters which man
can control. For example, the direction and magnitude of the thrust of a
rocket are parameters that can be controlled and used to influence the
rocket’s trajectory; similarly, the demand for an economic good is affected
by its price and the price can be set by the entrepreneur.