Science Philosophy and Practice: The Formulation and Impact of Naturalism, Reductionism, Determinism, and Positivism

views updated

Science Philosophy and Practice: The Formulation and Impact of Naturalism, Reductionism, Determinism, and Positivism


The “systems of thought” discussed below are not so much coherent systems as they are themes that appear and reappear with varying impact throughout the history of scientific thought. Before elements of the now standard “scientific method” were developed in practice by pioneers such as Italian astronomer and physicist Galileo Galilei (1564–1642), many philosophers attempted to reason a method for developing accurate information about the natural world.

From the days of Ancient Greece well into the Middle Ages, the quest for knowledge about the physical world occurred alongside what are now considered to be more metaphysical concerns. Metaphysics (roughly translated as “after physics”) is a branch of philosophy that concerns itself with an understanding of being as a whole, the meaning of life, and humanity's place in the universe. In science's formative days, legitimate methods for obtaining this information ranged from direct observation to the alleged use of divine revelation. Thinkers like French philosopher René Descartes (1596–1650) outlined a system of scientific inquiry, extracting it from the larger realm of concerns and methods and limiting it to subjects about which it could develop reliable information. Naturalism, reductionism, determinism, and positivism hold an important place in the family of concepts that constitute the modern understanding of scientific thought.

Historical Background and Scientific Foundations

Systems of thought are relative to time and place, and scientific thought is affected by these systems in two different but interrelated ways. One is their relation to the field of metaphysics. Science, as a discipline, is not directly concerned with metaphysics. Conflicts arise, however, when the practice of science or its conclusions influence metaphysics indirectly. One of the earliest examples of this conflict can be found in the Copernican Revolution, where, through scientific observation, Polish astronomer Nicolaus Copernicus (1473–1543) drew the conclusion that Earth was not the center of the universe, seemingly devaluing the Christian church's metaphysical claim that Earth was superlative among God's creations (and therefore necessarily at its physical center). A recent example of this conflict is the debate over the teaching of evolution in schools.

The second way in which systems of thought impact scientific thinking is their direct comment on the process of rational thinking or science itself.


Naturalism, as it applies to metaphysics, is the idea that the physical world is all that exists and that it is orderly. This is a deceptively simple formulation, however, as it has been interpreted to mean radically different things. The Greek thinker Thales (c.624–c.546 BC) has been called the first naturalist, because he argued that the entire universe was composed of a physical substance—water. Later Greek thinkers Democritus (c.460–c.370 BC), Lucretius (99–55 BC), and others followed his lead, theorizing a world composed of tiny particles—atoms. The common element among these theories, and the reason they can be called naturalistic, is their exclusion of gods or other supernatural divine forces in their conception of the universe.

Naturalistic thinkers did not all profess atheism however. Naturalism also describes a method for acquiring knowledge that focuses on observation of physical evidence to explain natural phenomena and ignores the question of a supernatural god altogether. This was especially useful during the Middle Ages and Renaissance, when a powerful religious authority regarded scientific activity with suspicion. During this time naturalism as a methodology gained popularity, not as an affront to the Christian faith, but as an extension of it—a way to understand divine creation. Scientists who professed belief in Christianity asserted that God operated through natural processes, and thus their work, rather than challenging their faith, reinforced it. Today, this type of naturalism, grounded in religious faith, is known as methodological naturalism, in contrast to ontological or metaphysical naturalism. Naturalism's lasting impact on scientific thought has been to delineate science from everything that is not science through the preponderance of physical evidence in the acquisition of knowledge and the search for a physical cause to natural phenomena.


The first modern reference to reductionism can be found in Descartes' work Rules for the Direction of the Mind. In this work Descartes outlines principles for the process of “rational analysis,” a method designed to produce an accurate understanding of the world. If naturalism provided one half of the conceptual weight of the scientific method, rational analysis provided the other. Rational analysis, especially when combined with experiment and observation, is considered the basis of the modern scientific method by some philosophers. Reductionism was essential to rational analysis and appears as a rule in Descartes' treatise. Reductionism is a method of analysis that understands a thing by reducing it to its parts. This method has led to our modern day understanding of the human body as a collection of organs, for example, or the atmosphere as a composition of different gases. Indeed, the drive to understand “the very simplest” elements of the universe has led scientists to discover atoms and subatomic particles.

Reductionism has a controversial edge with some philosophers when used to devalue any definition of “knowledge” that is not scientific knowledge. In practice, this type of reductionism, rather than maintaining science's characteristic indifference toward metaphysics, enters the debate by arguing that metaphysics, as a field of thought, is totally invalid. Whereas naturalism limits existence to the natural world and allows for interpretations of the divine, reductionism demands a categorical denial of anything divine or supernatural. In addition, it makes broader claims, particularly in relation to the options for the understanding of humanity's place in the world. For example, a reductionist is forced to account for human things like love, art, beauty, and friendship, in terms of subhuman chemical processes. This type of reductionism, though not properly scientific, is largely responsible for the sometime association of scientific thought with modern nihilism, the view that life is meaningless.


Implicit in science's longing to understand the natural world is the desire to predict, and therefore control, events. The scientific method even enshrines this idea of predictability, insisting that valid results of an experiment must be duplicable. In order to do this, one must be able to properly identify the cause of an event.

Then one must assume that every event does indeed have a cause. This idea immediately seems intuitive but also begs the question of a “first cause” for everything in the universe. Ironically, science's search for a first cause has thrown this intuitive truth into question, or at least rendered complex a seemingly simple proposition.

Determinism also questions the existence or nonexistence of human free will. If all events are caused by some other event, humans would seem to be morally “off the hook,” retaining no responsibility for their actions. This implication in particular has generated a great deal of resistance throughout history to the idea that nature operates according to set laws. Although this notion is generally accepted today, the conceptual paradox between natural laws and human free will remains, in many ways, unresolved.

Science has commented directly and indirectly on this debate since its inception. The idea that the universe operates according to laws—first introduced by the ancient Greek atomists and then formally in English physicist and mathematician Sir Isaac Newton's (1642–1727) Principia (1687)—suggests that events unfold in the universe with the predictability of balls in a game of billiards. The potential of these newly discovered laws was concisely described by French mathematician Pierre Simon de Laplace (1749–1827) in his seminal work Celestial Mechanics (1796). He argued that, with sufficient information about the present state of the universe, and with sufficient cognitive faculties, a man could predict “the movements of the greatest bodies of the universe and those of the tiniest….”

The “classical” description of a universe governed by knowable laws, while a philosophical conundrum, was not seriously called into question until the twentieth century, by German—American physicist Albert Einstein's (1879–1955) Theory of Special Relativity and the advent of quantum mechanics. The former offered a radical interpretation of time and, in turn, causality. Quantum mechanics suggested that phenomena were the result of a combination of both determinacy and chance. The latter, now the basis of modern scientific advances, demonstrates that matter behaves very differently at the atomic level than at the level of objects. Systems viewed at the quantum level appear to behave randomly or chaotically, confounding attempts to predict their activity with Newtonian laws of physics. Quantum mechanics speaks not of determinism but rather of probabilities.


The term “Positivism” was coined and developed by French philosopher Auguste Comte (1798–1857) in the mid–1800s. Positivism claims to be the application of scientific principles of inquiry to the great questions of philosophy and society. It was designed as an attempt to extend the reach of scientific thinking beyond traditional boundaries, while retaining a legitimately scientific process. It is both a worldview and a scientific methodology.


The Western rediscovery of Aristotle's (384–322 BC) philosophy in the twelfth century brought the theologically dominated medieval world into sharp conflict with Aristotelian logic as contained in the Book of Causes and other works of Arabic scholars. Although the original author of the Book of Causes is unknown (some scholars argue that it originated in ninth- or tenth-century Baghdad, others argue that it was written in twelfth century Spain), the book elaborated upon Aristotelian concepts by asserting that from each cause there results a certain order to its effects. In contrast to medieval beliefs regarding miracles, the Book of Causes argued that a god could not do anything contrary to the order he had already established. Aristotle's concept of a Prime Mover as a being that remains unmoved, unchanging, and impersonal was also incompatible with the Christian concept of a god who regularly intervened in the affairs of people through miracles. In addition, Aristotle's argument that the universe was circular and eternal contrasted with the Christian doctrine of creation.

Most early medieval scholars rejected the eternity of the universe as philosophically absurd. Some, however, made tenuous connections to Aristotle's Prime Mover by asserting that God was ultimately the cause of all phenomena, and that God worked through natural mechanisms.

Positivism begins by asserting that the only real knowledge available to human beings is knowledge of “phenomena.” Phenomena are understood to be objects and events as they are experienced in the world through the senses (the usual realm of scientific inquiry). This is contrasted with “noumena”—the essence or idea of a thing—as comprehended by the mind. Positivism echoes Descartes' reductionism and invokes naturalism's insistence on observation, but it makes far more ambitious claims than either of these systems. Comte suggested that scientific thinking is in fact the final stage in a historical progression of human thinking. Indeed, scientific thinking had the potential, when applied as positivistic philosophy, to “lay down a definite basis for the remodeling of society.”

The concept of progress is implicit in positivism. Though a common notion today, progress was a new idea in Comte's time and shaped much of the thinking of the late 1800s. Throughout the Enlightenment, scientific advances challenged the concept of a static social structure ordained by a supernatural god. Instead, it seemed possible to create a new society free of the injustices of the past, and science seemed to be the perfect guiding process. The optimism of this era proved intoxicating and birthed widely different movements. Comte was also a pioneer in sociology, which takes the “illnesses” of society as its object of study.

Modern Cultural Connections

The essential tensions between science, philosophy, and religion have not lessened over the centuries. These tensions over what constitutes reason—and of the interplay of reason and faith—manifest in debates over a wide range of issues that cross many cultural lines in present day.

Primary Source Connection

In a November 2005 article, Associate Press reporter Nicole Winfield reported on an event typical of the continuing tensions between ideologies.


VATICAN CITY—A Vatican cardinal said Thursday the faithful should listen to what secular modern science has to offer, warning that religion risks turning into “fundamentalism” if it ignores scientific reason.

Cardinal Paul Poupard, who heads the Pontifical Council for Culture, made the comments at a news conference on a Vatican project to help end the “mutual prejudice” between religion and science that has long bedeviled the Roman Catholic Church and is part of the evolution debate in the United States.

The Vatican project was inspired by Pope John Paul II's 1992 declaration that the church's 17th-century denunciation of Galileo was an error resulting from “tragic mutual incomprehension.” Galileo was condemned for supporting Nicolaus Copernicus' discovery that the Earth revolved around the sun; church teaching at the time placed Earth at the center of the universe.

“The permanent lesson that the Galileo case represents pushes us to keep alive the dialogue between the various disciplines, and in particular between theology and the natural sciences, if we want to prevent similar episodes from repeating themselves in the future,” Poupard said.

But he said science, too, should listen to religion.

“We know where scientific reason can end up by itself: the atomic bomb and the possibility of cloning human beings are fruit of a reason that wants to free itself from every ethical or religious link,” he said.

“But we also know the dangers of a religion that severs its links with reason and becomes prey to fundamentalism,” he said.

“The faithful have the obligation to listen to that which secular modern science has to offer, just as we ask that knowledge of the faith be taken in consideration as an expert voice in humanity.”

Poupard and others at the news conference were asked about the religion-science debate raging in the United States over evolution and “intelligent design.” Intelligent design's supporters argue that natural selection, an element of evolutionary theory, cannot fully explain the origin of life or the emergence of highly complex life forms.

Monsignor Gianfranco Basti, director of the Vatican project STOQ, or Science, Theology and Ontological Quest, reaffirmed John Paul's 1996 statement that evolution was “more than just a hypothesis.”“A hypothesis asks whether something is true or false,” he said. “(Evolution) is more than a hypothesis because there is proof.”

He was asked about comments made in July by Austrian Cardinal Christoph Schoenborn, who dismissed in a New York Times article the 1996 statement by John Paul as “rather vague and unimportant” and seemed to back intelligent design.

Basti concurred that John Paul's 1996 letter “is not a very clear expression from a definition point of view,” but he said evolution was assuming ever more authority as scientific proof develops.

Poupard, for his part, stressed that what was important was that “the universe wasn't made by itself, but has a creator.” But he added, “It's important for the faithful to know how science views things to understand better.”

The Vatican project STOQ has organized academic courses and conferences on the relationship between science and religion and is hosting its first international conference on “the infinity in science, philosophy and theology,” next week.

Nicole Winfield

winfield, nicole. “vatican: faithful should listen to science.” usa today (november 3, 2005).

See Also Science Philosophy and Practice: Ockham's Razor; Science Philosophy and Practice: Postmodernism and the “Science Wars”; Science Philosophy and Practice: Pseudoscience and Popular Misconceptions; Science Philosophy and Practice: The Scientific Method.



Comte, Auguste. A General View of Positivism. London: Routledge and Sons, 1907.

Descartes, René. Rules for the Direction of the Mind. Indianapolis: Bobbs Merrill, 1964.

Frankl, Viktor E. “Reductionism and Nihilism.” In Beyond Reductionism: New Perspectives in the Life Sciences. Edited by A. Koestler and J.R. Smythies. New York: Macmillan, 1970.

Laplace, Pierre-Simon. Celestial Mechanics. New York: Chelsea Publishing. 1966.

Lindburg, David C., and Ronald L. Numbers. When Science and Christianity Meet. Chicago: University of Chicago Press, 2003.

Mill, John Stuart. Auguste Comte and Positivism. London: N. Trübner & Co., 1866.

Russell, Bertrand, and Michael Ruse. Religion and Science. Oxford: Oxford University Press, 1961.

Wilson, Edward O. Consilience: The Unity of Knowledge. New York: Alfred A. Knopf, 1999.


Winfield, Nicole. “Vatican: Faithful Should Listen to Science.” USA Today (November 3, 2005).

Web Sites

The New England Complex Systems Institute. “Concepts in Complex Systems: Reductionism.” 2000. (accessed December 11, 2006).

Angela Scobey

About this article

Science Philosophy and Practice: The Formulation and Impact of Naturalism, Reductionism, Determinism, and Positivism

Updated About content Print Article


Science Philosophy and Practice: The Formulation and Impact of Naturalism, Reductionism, Determinism, and Positivism