What Are Science’s Operating Limits?

Modern science has dramatically changed the world for the better. All of us have benefitted from medical and technological advances. Because of that success, some people have concluded that science can answer all of humankind’s ultimate questions. This philosophy, called scientism (science is the only or best path to discovering truth), is to be differentiated from science (the study of the natural world through observation and experiment) and is reflected by such prominent secular scientists as Richard Dawkins, Peter Atkins, and Lawrence Krauss.

Does science have “operating limits”? In other words, are there areas of knowledge or questions that the scientific enterprise—because of its very nature—can’t adequately address? Let’s consider this issue.

Science: A Definition

Science involves a general inductive approach to obtaining knowledge about the world. It weighs probabilities and moves logically from the particular to the general. Scientific data generally comes directly through observation and experimentation about the physical universe. Thus science does an excellent job of explaining the physical mechanisms of the material world. It serves as a great tool for understanding the reality of that world. Science helps explain the what and how questions of life. And this practical aspect is what has made science such a successful, deeply valued human endeavor.

Science’s Limits

But science founders when it comes to the truly big questions of meaning, purpose, and significance. These are the ultimate why questions that people naturally and necessarily ask. For example, revealing that something happened in the physical world doesn’t explain why it happened or what it ultimately means. Biologist and philosopher Francisco Ayala has put it this way: “In matters of values, meaning, and purpose, science has all the answers, except the interesting ones.”1 And the eminent philosopher of science Karl Popper, reflecting a modest view of how science functions, stated: “It is important to realize that science doesn’t make assertions about ultimate questions—about the riddles of existence.”2

So what are science’s specific operating limits? They consist of key truths that science can’t formally prove but also that people can rationally affirm as being real and true:3

1. Mathematical and Logical Truths

Math and logic reflect laws and principles that are necessary for scientific theorizing and are foundational assumptions upon which science depends but that science can’t itself prove. Math and logic are conceptual (abstract) in nature rather than being empirically (sensory) derived. Science tends to confirm the truth of math and logic but it can’t justify these conceptual realities.

2. Metaphysical Truths

Metaphysical truths (relating to reality) include ideas like the existence of a real external world (not a mere illusion) and that minds exist (other than our own) that are capable of understanding that world. These critical ideas about reality are also foundational assumptions upon which science begins but can’t justify through the scientific method itself.

3. Ethical Truths

Objective moral truths and values exist (right, wrong, good, bad) and are required to do good science. For example, scientific experiments and the results they provide are valid only if they are conducted with exacting honesty and fair-mindedness. But these ethical and moral principles can’t be derived through science’s observational and empirical means.

4. Aesthetic JudgmentsAesthetics is that branch of philosophy that refers to the nature and appreciation of beauty, taste, and art. Beauty abounds in the natural world. But pure value judgments concerning the meaning and appreciation of beauty, taste, and art cannot be addressed by the scientific method. Again, value judgments about either morality or beauty are formed outside the operating lane of science.

5. Science Itself

The scientific enterprise is based upon critical assumptions that can’t be derived by the scientific method. Science cannot validate those assumptions nor can science tell us how scientific knowledge should be properly used. If scientists are to go about their work with any confidence, they must, for instance, believe in such presuppositions as:4

  • The objective reality of the cosmos
  • The basic intelligibility of the cosmos
  • The order, regularity, and uniformity of nature
  • The validity of mathematics and logic
  • The basic reliability of human cognitive faculties and sensory organs
  • The congruence between the human mind and physical reality
  • That an acceptable criterion for an adequate hypothesis exists
  • That what is observed in nature can provide clues and indicators of unobservable patterns and processes

These eight profound assumptions are just that: assumptions. That is, these preconditions for doing science are not first proven by science. Rather, scientists assume these ideas to be true before beginning to practice science. Science helps to confirm the truth of these preconditions of reality, but the scientific method itself did not establish or justify these prerequisite starting points. In this way, scientists operate on faith in these extraordinary givens—the necessary preconditions of intelligibility.

Ultimate Questions

There are many more areas of knowledge (historical, existential, experiential) that cannot be proven scientifically because they are not matters that can be repeated through critical observation and verified or falsified through the scientific method.
Nobel prize recipient Sir Peter Medawar (1915–1987) offered this statement concerning science’s operating limits:

That there is indeed a limit upon science is made very likely by the existence of questions that science cannot answer and that no conceivable advance of science would empower it to answer. These are the questions that children ask—the “ultimate questions” of Karl Popper. I have in mind such questions as: How did everything begin? What are we all here for? What is the point of living? It is not to science, therefore but to metaphysics, imaginative literature or religion that we must turn for answers to questions having to do with first and last things.5

Science, though robust and fruitful in addressing questions about the mechanisms of the natural world, nevertheless has real operating limits. However, the Christian worldview, which is responsible for giving rise to modern science, can augment science’s limited explanatory scope by offering reasonable explanations of questions about meaning, purpose, and significance.

Reflections: Your Turn

Does recognizing the limits of science in any way diminish the importance of this enterprise?


  1. Francisco J. Ayala, Darwin’s Gift to Science and Religion (Washington, DC: Joseph Henry Press, 2007), 177.
  2. Karl R. Popper, “Natural Selection and the Emergence of Mind,” in Evolutionary Epistemology, Rationality, and the Sociology of Knowledge, ed. Gerard Radnitzky and W. W. Bartley, III (La Salle, IL: Open Court, 1987), 141.
  3. Christian philosopher William Lane Craig identified these points as being outside of scientific verification yet justifiably rational and acceptable in his debate with atheist scientist Peter Atkins, “Does Science Prove Everything?” (April 21, 2010), https://www.youtube.com/watch?v=vxJQe_FefxY.
  4. For more on these preconditions of science, see Kenneth Richard Samples, Without a Doubt: Answering the 20 Toughest Faith Questions (Grand Rapids: Baker, 2004), 191–96.
  5. Peter Medawar, The Limits of Science (Oxford, UK: Oxford University Press, 1984), 66.

  One thought on “What Are Science’s Operating Limits?

  1. Gary Simmons
    December 13, 2019 at 5:12 am

    Very thoughtful question you have posed. From my perspective the realization of the limits of science in no way diminishes the importance of the enterprise; however, it does limit the overreaching claims made by some scientists that it is capable of discerning reality past these limits. And with even greater hubris that it is the sole enterprise capable of such an endeavor. This is why scientists need to develop at least a modest appreciation of philosophy and wiser yet, theology.


    • December 13, 2019 at 11:57 am

      Very good, Gary.


      Ken Samples

  2. December 29, 2019 at 11:10 am

    Very good. I would add that scientific paradigms are constantly changing (Kuhn) and that the scientific method itself is illogical, being based upon the fallacy of “affirming the consequent” (Clark).

    • December 29, 2019 at 1:42 pm

      Thanks, Scott.

      Ken Samples

  3. Ken Daniel
    January 12, 2020 at 6:46 pm

    Very interesting insights. At the beginning you state “Science involves a general inductive approach to obtaining knowledge about the world.” I think there may be an alternative way of looking at this. I can understand that the judge or jury in a court of law uses inductive reasoning to come to a conclusion about the alternative arguments presented by the lawyers. In government, two parties argue inductively as to the correct policy to take. Science cannot replace a judge or political party because science is totally dependent on deductive reasoning. Scientists at the fringe of knowledge set up clever experiments based on premises that they know to be true. The scientific method uses deduction, based upon these premises, to confirm or deny the hypothesis. The body of scientific knowledge is developed this way. This process doesn’t appear to be reasoning to the best explanation. The study of science in school is also deductively based. In your college physics class, there was only one correct answer to each problem. There was no reasoning to the best explanation. You needed to use the correct formula properly. Alternatively, a philosophy class is totally based upon inductive reasoning.

    • January 12, 2020 at 7:16 pm



      I’m a logic instructor at Biola University and I work for a science-faith based apologetics organization (RTB).

      Scientists actually use deductive, inductive, and abductive forms of reasoning. Abductive (or inference to the best explanation) is often used in hypothesis formation. But the enterprise of science (that is the scientific method) is an inductive process involving observation (empirical) and testing and generally weighing probabilities.

      There is a difference between the method of science (induction) and the forms or reasoning or arguments used in applying the data (deductive, inductive, abductive).

      Deductive argument are characterized by certainty (formal logic, geometry).

      Inductive arguments are characterized by probability (empirical prediction, science).

      Abductive arguments are characterized by plausibility (diagnostic thinking: detectives, doctors, lawyers).

      By the way, philosophy also involves deductive, inductive, and abductive forms or reasoning.

      I hope this helps.

      Ken Samples

  4. February 25, 2020 at 6:00 am

    “ These eight profound assumptions are just that: assumptions.”

    Hi, Ken. Good column. The young earth crowd constantly asserts that the scientific consensus is invalid because of “assumptions”. I press them repeatedly on this, and no one has ever responded with anything close to what you’ve listed. I agree with your list, but those particular assumptions do not support their contention.

    In a future post you mind address the possible limits of science itself, as discussed in “The End of Science” by Horgan. I think he’s really on to something, and lack of progress on key issues over the last 20 years vindicates his thesis.

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