Within the above framework, there are deep, often bitter, conflicts and controversies among liberals. Emerging from those controversies, out of classical liberalism, are a number of different trends within liberalism. As in many debates, opposite sides use different words for the same beliefs, and sometimes use identical words for different beliefs. For the purposes of this article, we will use "political liberalism" for the support of (liberal) democracy (either in a republic or a constitutional monarchy), over absolute monarchy or dictatorship; "cultural liberalism" for the support of individual liberty over laws limiting liberty for patriotic or religious reasons; "economic liberalism" for the support of private property, over government regulation; and "social liberalism" for the support of equality, over inequalities of opportunity. By "modern liberalism" we mean the mixture of these forms of liberalism found in most First World countries today, rather than any one of the pure forms listed above.

Some principles liberals generally agree upon:

Political liberalism is the belief that individuals are the basis of law and society, and that society and its institutions exist to further the ends of individuals, without showing favor to those of higher social rank. Magna Carta is an example of a political document that asserted the rights of individuals even above the prerogatives of monarchs. Political liberalism stresses the social contract, under which citizens make the laws and agree to abide by those laws. It is based on the belief that individuals know best what is best for them. Political liberalism enfranchises all adult citizens regardless of sex, race, or economic status. Political liberalism emphasizes the rule of law and supports liberal democracy.

Cultural liberalism focuses on the rights of individuals pertaining to conscience and lifestyle, including such issues as sexual freedom, religious freedom, cognitive freedom, and protection from government intrusion into private life. John Stuart Mill aptly expressed cultural liberalism in his essay "On Liberty," when he wrote,
“ The sole end for which mankind are warranted, individually or collectively, in interfering with the liberty of action of any of their number, is self-protection. That the only purpose for which power can be rightfully exercised over any member of a civilized community, against his will, is to prevent harm to others. His own good, either physical or moral, is not a sufficient warrant. ”

Cultural liberalism generally opposes government regulation of literature, art, academics, gambling, sex, prostitution, abortion, birth control, terminal illness, alcohol, and cannabis and other controlled substances. Most liberals oppose some or all government intervention in these areas. The Netherlands, in this respect, may be the most liberal country in the world today.
However, some trends within liberalism reveal stark differences of opinion:

Economic liberalism, also called classical liberalism or Manchester liberalism, is an ideology which supports the individual rights of property and freedom of contract, without which, it argues, the exercise of other liberties is impossible. It advocates laissez-faire capitalism, meaning the removal of legal barriers to trade and cessation of government-bestowed privilege such as subsidy and monopoly. Economic liberals want little or no government regulation of the market. Some economic liberals would accept government restrictions of monopolies and cartels, others argue that monopolies and cartels are caused by state action. Economic liberalism holds that the value of goods and services should be set by the unfettered choices of individuals, that is, of market forces. Some would also allow market forces to act even in areas conventionally monopolized by governments, such as the provision of security and courts. Economic liberalism accepts the economic inequality that arises from unequal bargaining positions as being the natural result of competition, so long as no coercion is used. This form of liberalism is especially influenced by English liberalism of the mid 19th century. Minarchism and anarcho-capitalism are forms of economic liberalism. (See also Free trade, Neo-liberalism, liberalization)

Social liberalism, also known as new liberalism (not to be confused with 'neoliberalism') and reform liberalism, arose in the late 19th century in many developed countries, influenced by the utilitarianism of Jeremy Bentham and John Stuart Mill. Some liberals accepted, in part or in whole, Marxist and socialist exploitation theory and critiques of "the profit motive", and concluded that government should use its power to remedy these perceived problems. According to the tenets of this form of liberalism, as explained by writers such as John Dewey and Mortimer Adler, since individuals are the basis of society, all individuals should have access to basic necessities of fulfillment, such as education, economic opportunity, and protection from harmful macro-events beyond their control. To social liberals, these benefits are considered rights. These positive rights, which must be produced and supplied by other people, are qualitatively different from the classic negative rights, which require only that others refrain from aggression. To the social liberal, ensuring positive rights is a goal that is continuous with the general project of protecting liberties. Schools, libraries, museums, and art galleries are to be supported by taxes. Social liberalism advocates some restrictions on economic competition, such as anti-trust laws and price controls on wages ("minimum wage laws.") It also expects governments to provide a basic level of welfare, supported by taxation, intended to enable the best use of the talents of the population, to prevent revolution, or simply "for the public good."
The struggle between economic freedom and social equality is almost as old as the idea of freedom itself. Plutarch, writing about Solon (c. 639 - c. 559 BCE), the lawgiver of ancient Athens, wrote:

“ The remission of debts was peculiar to Solon; it was his great means for confirming the citizens' liberty; for a mere law to give all men equal rights is but useless, if the poor must sacrifice those rights to their debts, and, in the very seats and sanctuaries of equality, the courts of justice, the offices of state, and the public discussions, be more than anywhere at the beck and bidding of the rich. ”

Economic liberals see positive rights as necessarily violating negative rights, and therefore illegitimate. They see a limited role for government. Some economic liberals see no proper function of government, while others (minarchists) would limit government to courts, police, and defense against foreign invasion. Social liberals, in contrast, see a major role for government in promoting the general welfare - providing some or all of the following services: food and shelter for those who cannot provide for themselves, medical care, schools, retirement, care for children and for the disabled, including those disabled by old age, help for victims of natural disaster, protection of minorities, prevention of crime, and support for the arts and sciences. This largely abandons the idea of limited government. Both forms of liberalism seek the same end - liberty - but they disagree strongly about the best or most moral means to attain it. Some liberal parties emphasize economic liberalism, while others focus on social liberalism. Conservative parties often favor economic liberalism while opposing social and cultural liberalism.

In all of the forms of liberalism listed above there is a general belief that there should be a balance between government and private responsibilities, and that government should be limited to those tasks which cannot be carried out best by the private sector. All forms of liberalism claim to protect the fundamental dignity and autonomy of the individual under law, all claim that freedom of individual action promotes the best society. Liberalism is so widespread in the modern world that most Western nations at least pay lip service to individual liberty as the basis for society.