One of the things discussed on the Pharyngula chatroom was the issue of morality. Religious conservatives have done a pretty good job at convincing people that the only alternative to conservative morality is no morality. The left-wing oppression-based morality is viewed not as a moral system but as an unnecessary drag on people.
At the heart of the idea that conservatives have a monopoly on morality is the notion that if your moral system cares deeply about something, you’ll view moral systems that are less concerned about it as depraved. For example, conservative sexual mores are based on idealized traditional marriages; since liberals say that any consensual sexual activity is fine, conservatives are aghast at how they don’t prefer traditional marriage to single-sex marriage and say they are relativists. For another example, feminists often view rape as especially bad since it’s emblematic of violence against women; therefore, they consider moral systems that tolerate rape as heinous.
Since liberal morality is based on a positive conception of rights, rather than a negative one of sin, it tends to be more permissive than most other moralities. People who want a rule book that will tell them what to do in every situation will not be comfortable with a system that says, “Do whatever you want, as long as you’re not infringing on other people’s rights.” If what they’re familiar with is a totalitarian scripture, they will not even recognize that system as a morality.
The other reason people often believe liberalism and secularism are amoral is that liberals and secularists rarely use the language of morality. The things liberal morality prohibits – murder, robbery, warmongering, denying health care to poor people – are easier to describe concretely as “things that hurt people” or “things that don’t work” rather than abstractly as “immoral acts.”
It’s not that liberals want to erase moral distinctions. It’s that the moral distinctions they focus on are very different from those conservatives do. Instead of dwelling on whether people should believe in any god, or on which sexual positions are approved, they just tell people not to hurt others, and concentrate on more important issues, like how to end third-world poverty.
I’ve argued several times by proxy that you can tell what a movement is about by looking at its internal arguments. When a movement takes seriously a positively nutty argument, it tars the entire movement; anti-choice conservatives who think the dilemma of whether to save a 5-year-old child or five embyros is real are insane even if at the end they decide to save the child.
Within liberalism, the internal arguments never take that form. The biggest intra-liberal split right now is between neo-liberals, who support free trade and economic growth as primary means of alleviating absolute poverty and view the IMF as a positive influence, and social liberals, who oppose the IMF’s model of growth and prefer a model that focuses on import replacement, nurturing local talent, and direct humanitarian aid.
Although the main intra-liberal discussions are about economic or social equality, there is a certain moral undertone to these discussions: it’s immoral to impoverish people or deny them equal rights, and it’s immoral to favor policies that have been shown to do either.
This principle looks trivial, but competing moral systems tend to ignore it too often. Libertarianism is openly anti-empirical; libertarians tend not to distinguish economic pragmatism from totalitarianism. Socialism goes beyond even focusing exclusively on equality, but instead opposes everything that could possibly be interpreted as imperialism. Conservatism is supposedly pragmatic, but its opposition to experimentation is deeply unpragmatic, and its claims that conservative values are necessary for economic growth or public safety contradict most available evidence.
The fact that liberalism’s main moral principles are those other moralities pay lip service to doesn’t make liberalism immoral or even amoral. It makes it more sensible. That a moral system pays attention to reality is a sign of strength rather than weakness. It’s trivial that murder, robbery, and rape are wrong. It’s evidently less trivial that impoverishing people is wrong, let alone that giving corporations more rights than individuals is wrong.