Liberty had a single central meaning for most of its history: government by law to serve the common good. Libertas meant life without subjection, except to public reason, expressed through elections. This last provision protects the rest and represents the point where republicanism and liberalism first explicitly diverged in the early nineteenth century. Even before this separation, partisans of monarchy frequently emerged to challenge liberty and question its republican antecedents. Thomas Hobbes, one of the subtlest and most lucid of such theorists, made a profound impression on subsequent debate, to the extent that republican liberty lost its meaning for many, and often even self-styled “liberals” and “republicans” now use Hobbesian terminology.