Legal officials argue differently for their case than Westerners. For instance, "predominant view among Soviet jurists in the 1920s was that Soviet law of that period was Western-style law appropriate for a Soviet economy that remained capitalist to a significant degree." This changed with the introduction of the planned economy and the term socialist law was conceived to reflect this in the 1930s. Hungarian legal theorist Imre Szabó acknowledged similarities between socialist law and civil law, but he noted that "four basic types of law may be distinguished: the laws of the slave, feudal, capitalist and socialist societies." Using the Marxist theory of historical materialism, Szabó argues that socialist law cannot belong to the same law family since the material structure is different from the capitalist countries as their superstructure (state) has to reflect these differences. In other words, law is a tool by the ruling class to govern. As Renè David notes, socialist jurists "isolate their law, to put into another category, a reprobate category, the Romanist laws and the common law, is the fact that they reason less as jurists and more as philosophers and Marxists; it is in taking a not strictly legal viewpoint that they affirm the originality of their socialist law." However, some socialist legal theorists such as Romanian jurist Victor Zlatescu differentiated between type of law and family of law. According to Zlatescu, "[the distinction between the law of the socialist countries and the law of the capitalist countries is not of the same nature as the difference between Roman-German law and the common law, for example. Socialist law is not a third family among the others, as appears in certain writings of Western comparatists." In other words, socialist law is civil law, but it is a different type of law for a different type of society.