Why do liberals advocate democracy?

Liberalism is the cornerstone to what we now call 'liberal democracy', which is characterised by fair and free elections, incorporating universal suffrage, and a civil society - such as a free media, freedom of protest, etc. The reasons that liberals advocate democracy are clear in some of the features of classical liberalism:

Firsly, Liberals believe in Rationalism. Liberalism is a child of the enlightenment, an intellectual movement that swept through 18th century Europe breaking many free from old ideas about religion. It enouraged people to think for themselves, and to think rationally: are my beliefs and actions sensible? Are they logical? Are they reasonable? People therefore became increasingly aware that leaders - such as monarchs - were not actually 'god-sent' and so the instituion of democracy (which incorporated the new belief that people could understand the world themselves and make their own decisions) was advanced.

Secondly, Liberals advocate Toleration. Another aspect of the enlightenment was the belief in the capacity of individuals to solve their problems through debate, rather than through conflict. As Voltaire, a French political philosopher, said: 'I detest what you have to say, but I will defend to the death your right to say it.'. Democracy represents the ability to debate in that it provides a means through which people can disagree, and influence the government, peacefully. This is reflected in the idea of a civil society, as many groups with different ideas and beliefs, can exist peacefully in a society by simply 'agreeing to disagree'.