Goals and Limits of Science

| By Thomas Burnett

Unifying scientific knowledge

In my previous post, we learned that science is a goal-directed activity. Here in this essay, we want to investigate one particular goal that encompasses a broad range of scientific disciplines: the quest to unify knowledge.

The ability to connect and explain seemingly unrelated phenomena is a hallmark of modern science and one of the key ways by which we evaluate the strength of theories. For instance, up until the end of 16th century, European intellectuals considered the motion of the heavens to be utterly distinct from motion here on earth. Celestial objects such as planets and stars moved in circles and earthly objects moved in straight lines. This notion, which was inherited from the ancient Greeks, accorded well with our common sense. But visionaries such as Johannes Kepler, Galileo, and Isaac Newton proposed that there were a set of underlying physical laws that determined all the motion in the universe, regardless of where it took place. Though their claims seemed counter-intuitive, their laws of motion predicted observable phenomena much more accurately than ever before.

A diagram of the apparent motion of the planets around the Earth, known as epicycles.

Other great scientific advancements also unified disparate areas of knowledge. In the 19th century, James Maxwell developed a theory with astonishing explanatory power, encompassing the fields of electricity, magnetism, and optics. Electricity was a complicated phenomenon exhibited by lightning strikes, static shocks, and a few strange fish. Seemingly unrelated was magnetism, evidenced by a certain kind of rock known as lodestone which attracted pieces of iron and had the uncanny ability to act as a directional device (a property familiar to anyone who has used a compass). The third field of exploration was optics, the branch of physics that studies the properties of light. Maxwell’s great achievement was to bring together all three of these fields through his electromagnetic theory of light.1

The effort to unify scientific knowledge continues unabated today. Physicists have been working towards unifying the four fundamental forces of nature: electromagnetism, the weak nuclear force, the strong nuclear force, and gravitation. In popular discourse this effort has been described as the “theory of everything”. Is this label merited? Will all knowledge eventually be unified by science?

Theoretical physicist Lisa Randall of Harvard University thinks the label “theory of everything” is a great misnomer. Even if physicists were able to unify all four of the basic forces, it would still not constitute a complete theory of everything. Knowledge of all the underlying properties of matter and energy would not be sufficient to fully understand all phenomena in the world. Instead, Randall thinks that we need explanations at a variety of scales, not just the most fundamental.2 That is why there are so many different scientific disciplines in existence today—and why they continue to multiply.

Reaching Limits

Though science has tremendous explanatory power and has expanded rapidly in the past several hundred years, it still has limits. In her book Knocking on Heaven’s Door, Professor Randall cautions us against thinking that our scientific knowledge is absolutely certain:

When scientists say we know something, we mean only that we have certain ideas and theories whose predictions have been well tested over a certain range of distances or energies. These ideas and theories are not necessarily the eternal laws for the ages or the most fundamental of physical laws.3

Though our understanding grows over time, we simply cannot measure every event in the universe at every moment. Scientific knowledge is reliable and well tested, but it is still contingent and subject to revision.

Another way science is limited is through its disciplinary boundaries. Institutions of higher learning are organized by academic departments, and these different departments are generally grouped into categories such as natural sciences, social sciences, and humanities. Though the boundaries are not completely airtight, they help each discipline to focus on questions that are appropriate for their specific methodology.

However, given the increasing role of interdisciplinary research and the rapid discoveries of science, some people believe that the methods of natural science should be extended to all phenomena, including those traditionally explored by the humanities and social sciences. Moreover, enthusiasts such as E.O. Wilson, author of the Pullitzer Prize-winning book On Human Nature, have suggested that natural science may eventually eclipse the humanities and social sciences altogether, making them superfluous.

Though it seems appealing to have a single, unified approach to all topics of investigation, this approach ignores the possibility that the very reason why natural science is so powerful is that it avoids certain topics and restrictsitself to particular domains. Questions of philosophy, history, theology, and the arts are often not amenable to strict quantification and reproducible testing. By imposing its methodology on these other areas, natural science could impoverish our understanding of the world rather than enrich it. In particular, science may not be well-equipped to answer certain questions related to purpose.

A Purposeless Universe?

Physicist Steven Weinberg is famous for saying, “The more the universe seems comprehensible, the more it also seems pointless.” But the fact is, when conducting scientific research, Weinberg and his colleagues aren’t directly looking for purpose, they are investigating what the universe is made of and how it works.4 This is the quest for structure and function, two areas in which science excels. Ultimate purpose, if there is any, may not be reducible to such knowledge alone.

On a smaller scale, we should not discount the fact that nearly all human activities, including science itself, are organized for specific purposes. But that raises the question, is there any purpose outside of human consciousness? Some scientists insist there is not. But are they justified in believing that in our incredibly vast cosmos, there is absolutely no other purpose than what we ourselves create? To take such a position implies a particular form of human uniqueness, a concept that many of these same scientists have usually been hesitant to embrace.

Indeed, the quest to discover the ultimate purpose of the cosmos presupposes that there is some non-human agent with an intention for that object. Thus, this issue is intimately connected with whether or not there is a self-conscious “mind of the universe”, as the ancient stoic Seneca described , or the “maker of heaven and earth” that we Christians have affirmed in our earliest creeds. However, if such an agent can't be sufficiently described by mathematics and/or material causes, then this subject is actually not a suitable target for scientific inquiry.6 In looking for purpose, we are looking beyond the limits of science.


Though humanity has a long, complicated, and contentious history, one characteristic that unites all societies is their longing to understand the world and their place within in. This quest has taken many forms: religious expression, literature, philosophy, art and science, all of which continue to thrive in our modern world. Some authors and popular figures depict science as completely distinct from other modes of human inquiry, but the fact remains that modern science largely emerged from and was enriched by Christian intellectual traditions, particularly natural philosophy.7 This does not diminish the value of science by any means—to the contrary, by carefully examining the conceptual foundations of science, its goals and limits, we are better prepared to grasp its true potential.


1. Artigas, Mariano. The Mind of the Universe: Understanding Science and Religion. Radnor, Penn: Templeton Foundation Press, 2000, p86.
2. Randall, Lisa. Knocking on Heaven's Door: How Physics and Scientific Thinking Illuminate the Universe and the Modern World. New York: Ecco, 2011.
3. Randall, p8
4. Ruse, Michael. Science and Spirituality: Making Room for Faith in an Age of Science. Cambridge University Press, 2010, p 144.
5. Artigas, introduction
6. Hutchinson, Ian. Monopolizing Knowledge: A Scientist Refutes Religion-Denying, Reason-Destroying Scientism. Belmont, MA: Fias Publishing, 2011, p71
7. To learn more about the relationship between Christianity and the development of modern science, I recommend the following books: Edward Grant, Science and Religion, 400 BC to AD 1550: From Aristotle to Copernicus (The Johns Hopkins University Press, 2006); James Hannam, The Genesis of Science: How the Christian Middle Ages Launched the Scientific Revolution (Icon Books, 2009); Peter Harrison, The Bible, Protestantism, and the Rise of Natural Science (Cambridge University Press, 2001).


About the Author

Thomas Burnett

Thomas is a former BioLogos Associate Editor. He currently works in science communications at the National Academy of Sciences, and he has also worked with the American Scientific Affiliation and the American Association for the Advancement of Science. He has degrees in philosophy and the history of science from Rice University and University of California, Berkeley.