What is less well known is that Acton was not a pithy journalist, but a scholar and historian who made it his life work to trace out the history of liberty. He traced the origin of liberty back to Jesus Christ. On February 26, 1877 he delivered his lecture "The History of Liberty in Antiquity," to the members of the Bridgnorth Institution at the Agricultural Hall. After tracing out various ultimately failed attempts by ancient thinkers to reign in the state, he cites Jesus' response to the Pharisees, "Render unto Caesar the things that are Caesar's and unto God the things that are God's" as the moral impetus necessary for winning liberty in Western Civilization.
As Acton explained,
All that Socrates could effect by way of protest against the tyranny of the reformed democracy was to die for his convictions. The Stoics could only advise the wise man to hold aloof from politics, keeping the unwritten law in his heart. But when Christ said: “Render unto Cæsar the things that are Cæsar’s, and unto God the things that are God’s,” those words, spoken on His last visit to the Temple, three days before His death, gave to the civil power, under the protection of conscience, a sacredness it had never enjoyed, and bounds it had never acknowledged; and they were the repudiation of absolutism and the inauguration of freedom. For our Lord not only delivered the precept, but created the force to execute it. To maintain the necessary immunity in one supreme sphere, to reduce all political authority within defined limits, ceased to be an aspiration of patient reasoners, and was made the perpetual charge and care of the most energetic institution and the most universal association in the world. The new law, the new spirit, the new authority, gave to liberty a meaning and a value it had not possessed in the philosophy or in the constitution of Greece or Rome before the knowledge of the truth that makes us free.