section_path: Philosophy/Major themes
section_name: Major themes
paragraph_text: Major themes
  
  Although all liberal doctrines possess a common heritage, scholars frequently assume that those doctrines contain "separate and often contradictory streams of thought". The objectives of liberal theorists and philosophers have differed across various times, cultures and continents. The diversity of liberalism can be gleaned from the numerous qualifiers that liberal thinkers and movements have attached to the term "liberalism", including classical, egalitarian, economic, social, the welfare state, ethical, humanist, deontological, perfectionist, democratic, and institutional, to name a few. Despite these variations, liberal thought does exhibit a few definite and fundamental conceptions.
  
  Political philosopher John Gray identified the common strands in liberal thought as individualist, egalitarian, meliorist and universalist. The individualist element avers the ethical primacy of the human being against the pressures of social collectivism; the egalitarian element assigns the same moral worth and status to all individuals; the meliorist element asserts that successive generations can improve their sociopolitical arrangements, and the universalist element affirms the moral unity of the human species and marginalises local cultural differences. The meliorist element has been the subject of much controversy, defended by thinkers such as Immanuel Kant, who believed in human progress, while suffering criticism by thinkers such as Jean-Jacques Rousseau, who instead believed that human attempts to improve themselves through social cooperation would fail.
  
  The liberal philosophical tradition has searched for validation and justification through several intellectual projects. The moral and political suppositions of liberalism have been based on traditions such as natural rights and utilitarian theory, although sometimes liberals even request support from scientific and religious circles. Through all these strands and traditions, scholars have identified the following major common facets of liberal thought: