At its broadest, liberalism is about improving people’s lives while treating them alike and shielding them from undue power. Four ideas in particular seem to have guided liberals through their history.
The first is that the clash of interests and beliefs in society is inescapable. Social harmony, the nostalgic dream of conservatives and the brotherly hope of socialists, is neither achievable nor desirable – because harmony stifles creativity and blocks initiative. Meanwhile conflict, if tamed and put to use as competition in a stable political order, could bear fruit as argument, experiment and exchange.
Secondly, human power is not to be trusted. However well power behaves, it cannot be counted on to behave well. Be it the power of state, market, social majorities or ethical authorities, the superior power of some people over others tends inevitably to arbitrariness and domination unless resisted and checked. Preventing the domination of society by any one interest, faith or class is, accordingly, a cardinal liberal aim.
Liberals also hold that, contrary to traditional wisdom, human life can improve. Progress for the better is both possible and desirable, for society as a whole and for people one by one, through education above all, particularly moral education.
Finally, the framework of public life has to show everyone civic respect, whatever they believe and whoever they are. Such respect requires not intruding on people’s property or privacy; not obstructing their chosen aims and enterprises; and not excluding anyone from such protections and permissions because they’re useless to society or socially despised.
…These four key ideas also distinguished liberals, point for point, from 19th-century socialists and conservatives, and in the 20th century from fascists and communists. They continue to distinguish liberals from their present-day rivals: competitive authoritarianism (China), ethnic nationalism (India), military populism (Egypt, Venezuela), nationalist Islamism (Turkey) and theocratic Islamism (Iran).
Like I said before, works for me, good enough. There's always room to quibble over details, but I don't have any serious quarrels with that.