Legal realism emerged in the early twentieth century as a challenge to the prevailing formalist view that judges decide cases through a purely logical, syllogistic process. Formalists argued that the law is a complete and autonomous system of rules, and that a judge's task is simply to find the correct rule and apply it to the facts of a case, much like a mathematician solves an equation. Realists, however, contended that this view is an illusion. They argued that legal rules are often indeterminate and that judges are influenced, often unconsciously, by their personal values, social backgrounds, and political convictions. For a realist, the law is not a static body of rules but is instead defined by the actual behavior of judges and the practical consequences of their decisions. This perspective led to a call for more empirical study of the legal system and a greater focus on the social policy implications of judicial rulings, as realists believed that law should be used as a tool for social improvement.