New occasions teach new duties,Lowell was speaking of slavery, and his lines became part of a popular Protestant hymn, no doubt Unitarian. The slave trade that I spoke of here these past few days was, of course, initiated and carried on by good Christian men. When the American Founding Fathers met in Philadelphia to hammer out a constitution for the new republic, slavery was the elephant in the room, recognized by many as an abomination, but generally ignored in the deliberations by tacit agreement that no federal arrangement was otherwise possible. (The representative from Georgia insisted that the Bible placed its benediction on the institution of slavery.) Madison, Jefferson, Washington, and many others we take to be paragons of virtue were slave holders. Seventy years would pass, and a horrendous civil war fought, before the "ancient good" became at last by law uncouth.
Time makes ancient good uncouth.
They must upward still and onwards
Who would keep abreast of truth.
Another century later, when I was growing up in Chattanooga, it was thought good and appropriate by my white neighbors that blacks and whites be kept strictly separate in schools, churches, and public facilities. And heaven forbid that blacks might exercise their right to vote. Thanks to the civil rights movement of the 1960s that "good" too became uncouth. And so it goes, onwards and upward, not so much keeping abreast of truth as making up truth as we go.
The very idea of the progress of truth is associated with the Scientific Revolution of the 17th century. Until that epic transformation of human culture, truth was defined by the authority of the past, as embodied in ancestors, holy books, or divinely appointed prelates and kings. Which is not to say that liberal spirits had not always been with us, but not until the time of Bacon and Galileo did it become common to suppose that ancient truth might be amendable. The Earth-centered universe was a venerable truth that Copernicus, Kepler and Galileo showed to be untenable. And if the Earth could be moved from its central position in the cosmos, then everything else was up for grabs -- the divine right of kings, the power of the Church to burn heretics, slavery.
By its commitment to an open-ended search for truth, science has been the great engine and friend of political and religious liberalism. It is no coincidence that the present foes of science in American public schools are the same unyielding adherents to ancient authority who would deny, for example, the civil rights of gays or a living wage for the poorest of the poor.