Of course, the Enlightenment did not spring from nothing. It, too, had antecedents. In "Ideas Have Consequences," Richard M. Weaver, a noted historian of ideas at the University of Chicago, traces the rudiments of the modern age to fourteenth-century William of Ockham (1284-1347), who was an early proponent of nominalism, a teaching that denies that anything universal has real existence. Many scholars include John Duns Scotus (1265-1308) as a co-conspirator with Ockham in undermining settled principles of natural law.

The issue, Weaver notes, "is whether there is a source of truth higher than, and independent of man. The practical result of nominalist philosophy is to banish the reality which is perceived by the intellect (or spirit) and to posit as reality (only) that which is perceived by the senses." The consequence of this way of thinking is to deny things that cannot be known or understood except through physical experience.

This change in the definition of what is real was an early step in the development of two ideas that were central to Enlightenment thinking. First, Weaver notes that "with the denial of objective truth there is no escape from the relativism of 'man, the measure of all things.' " Second, the notion that all knowledge can only come from the application of our senses is at the heart of the Enlightenment-created doctrine of the scientific method.

Both William and Duns Scotus (often called "The Blessed") were devout men of deep faith. Neither had any intention of undermining the faith of others. Yet "though it couldn't be clear at the time, we with hindsight can recognize (the writings of Duns Scotus and Ockham) as a major turning point in the history of Western civilization, an important step towards that primacy of the individual which defines our culture," and lies at the heart of the Enlightenment project (Charles Taylor, "A Secular Age").

Next week: Descartes and Spinoza

Joseph A. Cannon is editor of the Deseret News.