What is Liberalism?

I wonder if Cass would agree: Liberalism is not fundamentally a fixed political ideology or a contingent historical doctrine; it is an enduring aspiration for the human condition itself—one that seeks to cultivate societies where individuals can pursue diverse visions of a good life, free from arbitrary coercion, amid mutual respect, pluralism, and institutions that safeguard dignity and self-governance.

I feel like Sunstein is would say freedom of speech is a necessary condition for liberalism. If man is to get along in society then there is a need for pluralism, for an admission that others, with other ideas, will group together and their choices as a path to freedom are to be respected. Thus, it is necessary to be able to speak freely about differences and similarities in the practical ways when people live side-by-side. In fact one might even say that free speech illicits a competitive pluralism where the investigation of others and a distinction of differences sets up a truth-finding for each.