Americans most commonly think of liberalism in a political context, but liberal principles have a much larger and wider application. Liberal principles reflect a worldview that emanates from the very roots of modern consciousness, and affect our basic assumptions about religion and economics, as well as politics. The liberal worldview springs from a primal source in the human longing for freedom and dignity. The depth and scope of its effect means that liberal principles cannot permanently be suppressed. They reflect a deeply human yearning.
I have argued elsewhere that a liberal perspective underlies most of what Americans treasure in modern society.  The liberties protected by our constitution, the economic freedom of entrepreneurship and association, and the religious freedoms of expression all derive their energy and owe their genesis to liberal ideas. Not the liberal that is differentiated from conservative, but the set of liberal principles differentiated from feudalism. The foundations of liberalism emerged during the Renaissance as a response to the constraints of feudal power. Profound changes in human consciousness and philosophy followed, and these changes altered the way people in the West perceived the world. Liberalism defined a new consciousness, which is our worldview.
In his book, A Theory of Everything, Ken Wilber  puts forth a grand framework for studying and understanding the individual and collective aspects of the human being. The development of organisms, individuals, and societies generally moves toward higher levels of consciousness. Wilber demonstrates that there is wide, general agreement on this notion from scientists and researchers across most disciplines of study. But the development is not a straight line; it unfolds in waves or lines, and includes different states and types of consciousness.  Although development is a messy, fluid, overlapping, intermeshing affair, it is nonetheless real.
According to Wilber, the essence of the feudal, Middle-Ages type of consciousness is domination by powerful people, gods, and archetypes; empire, honor, and glory; the early sense of self as separate from the tribe, yet not fully differentiated; righteous order, rigid social hierarchy, and literal belief systems.  Material progress is won mostly by conquest.  Religious experience is mediated. Different aspects are stronger in different locations at different times, but the general trend of society and consciousness takes this form. Honor, order, duty, obedience, allegiance—these were the psychic currencies of feudal consciousness, and they went hand-in-hand with a feudal church-state partnership and the economy of conquest. This medieval consciousness dominated the Western world throughout that historical period.
Using his model, Wilber argues that a major development occurred in western consciousness with the Renaissance. Europeans began to differentiate aspects of being. For example, with the birth of modernity art, morals and science became differentiated.  Politics, economics, and religion separated into their own spheres. We began to see ourselves in the differentiated categories of state, self, and society. 
Renaissance philosopher René Descartes (1596-1650) laid the foundation of modern liberal philosophy: reliance on reason and the pre-eminent importance of individual experience. “I think, therefore I am,” he said. Although Descartes was overly mechanistic in his view of nature and the universe, these two ideas—reason and the individual—developed as pillars of modern liberal consciousness.
Modern liberal consciousness developed an increased awareness of the self, and the individual’s ability to know via experience. Thus, an individual’s own experience and empirical sensibility became a more trusted guide to reality than the blind trust placed in king, clergy or nobleman to dictate reality on the individual’s behalf. The Reformation was strongly influenced by this insight. Free enterprise provided the economic basis of the individual’s right to decide for himself, and liberal democracy enabled the individual expression of political will which would eventually overthrow the feudal system, the aristocracy, and later fascism and communism.
In the individual the new consciousness was fueled by the rediscovery of reason. Science and art moved forward with a focus on creativity, questioning, and searching. The self became more individual and less group-oriented—less loyal, dependent, and dutiful, seeking expression in different ways; science and experience were found to be particularly adept at empowering such expression. People trusted what they could see, study, and reason for themselves, rather than obediently accepting what they were told to believe. Natural laws could be learned, mastered and manipulated. The original vanguard of the Renaissance flowed into the larger culture.  Out of it came a new way of thinking and perceiving the world—what I call modern liberal consciousness.
The new liberal consciousness became the basis for a new way of life, a new way of relating to the world, and a whole new set of challenges, problems, and opportunities. Descartes, Newton, Copernicus and other scientists changed our perception of the world. The dynamic interplay between society and consciousness created substantial changes for both. The religious, economic and political structures were challenged, as were the limits imposed on personal education, knowledge, creativity, and brilliance. Modern consciousness emerged as an engagement with reason, law, individual achievement, and self-authority—the very essence of liberal ideas and principles.
Americans will do well in our current political debate to keep in mind the difference between modern liberal consciousness and pre-modern feudal consciousness. He first engenders democracy, the second various contemporary forms of feudal power. These are not idle contemplations; what we imagine collectively is what we will manifest.
 See Call to Liberty: Bridging the Divide Between Liberals and Conservatives, Scarletta Press, 2006.
 Wilber, Ken. A Theory of Everything, Shambala, Boston, 2000.
. Op. cit., p. 43. I owe the notion of unfolding waves of consciousness to Wilber.
 Op. cit., pp. 9-10.
 Friedman, Benjamin. The Moral Consequences of Economic Growth. Alfred A. Knopf, New York, 2005.
 Wilber. Marriage, op. cit.