The ‘common sense’ argument for evolution



In trying to convince readers that the Darwinian worldview is true, it is commonly argued that the case for evolution is ‘common sense’, as though this expression is solid proof that ends the argument. An example is the headline of one article that exclaimed: “Evolution is plain common sense.”1 Another example is the article “Common Sense ‘Expelled’ in New Movie”, which concludes that it is common sense that creation and Intelligent Design are false and evolution is true.2 Then there exists the “Common Sense Atheism” website that uses “common sense” to prove evolution and disprove Intelligent Design.

The term common sense is often used as “proof”, especially if the idea it is used to support is commonly accepted as fact by most scientists or the general public. If one concludes that it is obvious to him or her that evolution is correct, but cannot articulate why, “it is common sense” may be used as a reason. Unsurprisingly, evolutionists claim the common-sense facility itself evolved as did everything else.3

Examples can be found everywhere, especially in the mass media. For example, below the headline referenced above, “Evolution is plain common sense”, the reporter wrote:

Many people believe ridiculous things, especially when at an impressionable age, but most will eventually, shuffle off such beliefs as time goes on and they become wise with age. However some remain and in the case of Christianity, this is the belief in creationism or its nefarious cousin Intelligent Design and hence they willingly deny biological and galactic evolution.1

Another example is “Like much evolutionary theory, this is just applied common sense.”4

One of many examples is found in the words of Richard Dawkins, who often uses the phrase “common sense”. He says that the religious mind flies in the face of “everything that ordinary common sense and human feeling would see as important.”5 He then adds that common sense evolved like everything else, writing that “Common sense lets us down, because common sense evolved in a world where nothing moves very fast, and nothing is very small or very large.”6 Then he defines a “philosopher as someone who won’t take common sense for an answer.”7 Another example is Jerry Coyne, who wrote that early geologists ordered the different rock layers “using principles based on common sense” to develop the geological strata on which evolution is based.8

The phrase ‘common sense’ is also used by the other side. Intelligent Design supporter Doug Axe, in his new book wrote that common science—using the word science instead of sense—will prove Darwinism wrong, adding that he “called it common science to emphasize the connection to common sense.”9 He also states, “To stand your ground in the face of … intellectual intimidation [by Darwinists], you’d need a simple, unassailable common-sense argument.”10 The problem that “most players are wearing the Darwin jersey” is incorrect, and the evidence is “not to the technical disciplines but rather to common sense and common science.”11

Axe concludes that “common science and common sense naturally lead us to attribute life to God, even as the children of atheists do.”12 To be fair his book extensively documents his conclusion, and by common sense, he refers to logical conclusions based on evidence. Not all writers do this.

Defining ‘common sense’

The phrase ‘common sense’ is often used in both speaking and writing to refer to knowledge shared by all, or most, of the public, thus it is common. “Sense” refers to the human ability to receive and react to stimuli, especially light and sound. It was at one time believed that common sense was a special brain faculty that united and interpreted the impressions of all the five senses. In other words, it was an internal mental process that accurately combined information to form a conclusion based on the information received from the senses.

Except in a loose way as a function of the brain, spinal cord, and the gland system, this ‘faculty’ does not exist. Nonetheless, the use of the expression today often clearly implies this older meaning. The most accepted definition of common sense is “good, sound, practical sense; general sagacity.” Webster’s Dictionary defines it as practical judgment or the use of intelligence to achieve ordinary good sense.

A valid use of the expression refers to blatantly obvious conclusions, such as the earth is round; one cannot fly from Paris to Detroit in five minutes; or the sun rises in the east and sets in the west. In order to make sound “practical judgments”, though, one must have factual input; and the amount of knowledge about any one subject varies greatly from person to person. In addition, all judgments rely heavily on feelings, attitudes, prejudices, and individual experiences. The result is that conclusions tend to be somewhat divorced from facts. Good evidence to my mind clearly may not be good evidence to yours.

Therefore, common-sense conclusions are based on what the person has learned, including assumptions and, especially, one’s past experiences. As experiences differ among people, one person’s “common sense” conclusion may not agree with someone else’s. Thus, the clichés “common sense is not very common” and “common sense is a rather uncommon science”, are often directed against one who sees things differently than the speaker.

The variety of viewpoints that the phrase ‘common sense’ is used to support is illustrated by a Flat Earth Society brochure. This organization believes that the earth is physically pancake-shaped, and they are dedicated to “proving” this view, which to them is plain common sense. A brochure describing the requirements for membership stated:

Membership is open to all persons of integrity who have a serious and abiding interest in the Society and who subscribe to [its] … aims and constitution … . The Society does not indulge in vulgar proselytizing, but depends for the diffusion of its ideas upon the dedication of its membership to the ageless testimony of common sense.

The “ageless testimony of common sense” means that, when on the earth’s surface, unaided visual sensory input normally conveys only the earth’s apparent flatness. Common sense is used in this case to “prove” a concept to avoid relating direct evidence. The expression, “ageless testimony of common sense” is unlikely to bring forth an intelligent response because there is little except an expression to which one can respond.

Statements like, I “very seldom believed” what was told to me like intelligent design unless “it made a lot of common sense”, mean that one seldom believes someone else unless it sounds reasonable. If something didn’t fit in to his worldview, regardless of its validity, he may not accept it. Conversely, something that appears reasonable may be incorrect, as illustrated by optical illusions. The more incongruence between an idea and our cognitive set, likely the more we will disagree with it, and thus the less it sounds like a common-sense conclusion. If the phrase “common sense” was replaced by “my conclusion, ideas, prejudices, etc.,” this statement would be both clearer and more honest. Writers should support their conclusions with evidence instead of appealing to the dictates of common sense.

Use of the term in lieu of supportive data

As in the above illustrations, the phrase ‘common sense’ is often used in lieu of supportive empirical data. When pressed to defend one’s position, one can avoid giving valid reasons by responding with, “It’s common sense.” This is especially true if one cannot provide factual data or present coherent logical arguments to back up one’s position. If one had factual data, he or she probably would supply it: “A 1999 study by Taylor showed that ….”

A person may believe that a conclusion is clearly valid without being able to give specific reasons as to why. We all learn a great deal that we cannot immediately recall, but, nonetheless, affects our decision-making. A correct conclusion may be partially the result of a subconscious evaluation of data without full awareness of the data that the mind used to make the decision. But even here, using the phrase ‘common sense’ as support for a conclusion is not justified. Avoiding answers like “It’s common sense” may force an examination of the actual basis used to make the decision. As it was made on some basis, we should at the least attempt to construct that basis, and not gloss over this necessary process with, “It’s common sense.”

Common sense as magic

It is even sometimes implied that a conclusion “from” or “of” common sense is somehow better than a conclusion formed by other means. It is as if there is something mystical or magical about common sense deductions. For this reason, especially in scholarly writing, the words “common sense” can obscure the actual basis of one’s argument.

The conclusion is that the phrase ‘common sense’ is misused even by the educated elite. Harvard University Professor of Government, Adam Ulam said in a New Republic article it “would have been much better had our ‘best and brightest’ [referring to the leading government officials] heeded Poirot’s advice, rather than that of professors, and consulted the ‘little gray cells,” i.e., used common sense rather than stultifying models.13 In other words, Ulam claims they would have made better decisions had our government officials relied on their own 'common sense' rather than consulting those who spent their lifetime researching their respective areas!

The phrase common sense is often used because it has a strong appeal. Use of it in a book title is likely to strike a responsive chord in those who might otherwise pass up the volume. The 2017 Books in Print lists over 60 titles that begin with the words “common sense”, e.g. Commonsense Darwinism: Evolution, Morality, and the Human Condition.14

Summary and conclusions

The phrase ‘common sense’ is a much used and abused phrase with little or no meaning, often implying some non-existent brain skill. Not being able to resort to “It’s common sense” would force one to find evidence or valid reasons to back up what is said. No longer could the populace refer to common sense as proof of a supposition or prejudice. No longer could we pass off unsupported statements with the “rubber stamp” proof of “It’s common sense.” For these reasons, our language would be better off without this phrase.

Published: 13 November 2018

References and notes

  1. Freeman, T., Evolution is plain common sense, news24.com/MyNews24/Evolution-is-plain-common-sense-20141014, 14 October 2014. Return to text.
  2. Radford, B., Common Sense ‘Expelled’ in New Movie, livescience.com/2430-common-sense-expelled-movie.html, 3 April 2008. Return to text.
  3. Wilkins, J.S., The Evolution of Common Sense, blogs.scientificamerican.com/guest-blog/the-evolution-of-common-sense/, 24 May 2011. Return to text.
  4. Like much evolutionary theory, this is just applied common sense, forum.wordreference.com/threads/like-much-evolutionary-theory-this-is-just-applied-common-sense.2146597/, 12 May 2011. Return to text.
  5. Dawkins, R., The God Delusion, Houghton Mifflin, Boston, p. 313, 2006. Return to text.
  6. Dawkins, ref. 5, p. 364 Return to text.
  7. Dawkins, ref. 5, p. 83 Return to text.
  8. Coyne, J., Why Evolution is True, Penguin Books, New York, p. 23, 2010. Return to text.
  9. Axe, D., Undeniable: How Biology Confirms Our Intuition That Life Is Designed, Harper-One, New York, p. 60, 2016. Return to text.
  10. Axe, ref. 9, p. 100. Return to text.
  11. Axe, ref. 9, p. 189. Return to text.
  12. Axe, ref. 9, p. 232 Return to text.
  13. Ulam, A. Agatha Christie: Murder and Class, The New Republic, p. 23, 31 July 1976. Return to text.
  14. Lemos, J., Commonsense Darwinism: Evolution, Morality, and the Human Condition, Open Court, New York, 2008. Return to text.