The ideology of the Communist Party of the Soviet Union (CPSU) was Bolshevist Marxism–Leninism, an ideology of a centralised command economy with a vanguardist one-party state to realise the dictatorship of the proletariat. The Soviet Union's ideological commitment to achieving communism included the development of socialism in one country and peaceful coexistence with capitalist countries while engaging in anti-imperialism to defend the international proletariat, combat capitalism and promote the goals of communism. The state ideology of the Soviet Union—and thus Marxism–Leninism—derived and developed from the theories, policies and political praxis of Lenin and Stalin. Marxism–Leninism Marxism–Leninism was the ideological basis for the Soviet Union. It explained and legitimised the CPSU's right to rule, while explaining its role as a vanguard party. For instance, the ideology explained that the CPSU's policies, even if they were unpopular, were correct because the party was enlightened. It was represented to be the only truth in Soviet society, and with it rejecting the notion of multiple truths. In short, it was used to justify CPSU Leninism as being a means to an end. The relationship between ideology and decision-making was at best ambivalent, with most policy decisions taken in the light of the continued, permanent development of Marxism–Leninism, which, as the only truth, could not by its very nature become outdated. Despite having evolved over the years, Marxism–Leninism had several central tenets. The main tenet was the party's status as sole ruling party. The 1977 Constitution referred to the party as the "leading and guiding force of Soviet society, and the nucleus of its political system, of all state and public organizations, is the Communist Party of the Soviet Union." State socialism was essential, and from Joseph Stalin until Mikhail Gorbachev official discourse considered private social and economic activity as regarding the development of collective consciousness and of the economy. Gorbachev supported privatization to a degree, but based his policies on Vladimir Lenin's and Nikolai Bukharin's view on the New Economic Policy of the 1920s, and supported complete state ownership over the commanding heights of the economy. Unlike liberalism, Marxism–Leninism stressed not the importance of the individual, but rather the role of the individual as a member of a collective. Thus defined, individuals had only the right to freedom of expression if it safeguarded the interests of the collective. For instance, in the 1977 Constitution Marxism–Leninism it was stated that every person had the right