Step 1: Understanding the Concept:
The question asks for the core idea of Rudolf von Ihering's theory of 'social utilitarianism'. Ihering was a German jurist who belonged to the sociological school of jurisprudence.
Step 2: Detailed Explanation:
Ihering's main contribution was his insistence on law as a tool to serve a social purpose. His philosophy is often summarized by the statement that "law is a means to an end." The 'end' is the welfare of society.
Let's analyze the options:
- (A) greatest number of people should get greatest pleasure: This is the principle of hedonistic utilitarianism, most famously associated with Jeremy Bentham, not Ihering.
- (B) the essential body of legal rules is always based upon the social “facts” of law: This is more closely associated with Eugen Ehrlich's theory of "living law".
- (C) a balance is to be struck between the competing interests in society: This is the theory of "social engineering" propounded by Roscoe Pound, who saw the jurist's task as balancing conflicting interests in society.
- (D) law is a means to social ends: This perfectly encapsulates Ihering's view. He believed that the purpose of law is to protect interests and resolve conflicts between individual interests and social interests, with the ultimate goal being the advancement of society. Law is a tool to achieve this social purpose.
Step 3: Final Answer:
The central tenet of Ihering's theory of social utilitarianism is that law is an instrument for serving the needs of society, or simply, law is a means to social ends. Therefore, option (D) is the correct answer.