Newsweek recently featured an article in which the author, Jess Thompson, reports that researchers have discovered that common sense “may not be so common after all.”

Whether you’re shocked by that news or not, you will find that by the time you reach the claims examined by the researchers as part of their “study” you get the sense that something is off. Here is a partial list of the claims the researchers examined:

… perception is the only source of knowledge, what is not perceived does not exist;” “rudeness is the weak man’s imitation of strength;” “triangles have three sides;” “numbers don’t lie, we should always trust the math …

Your own common sense may already be telling you that these claims seem remote from the definitions you have for common sense.

Let’s go back to basics to try to get reoriented. I suggest we consult the dictionary. My dictionary defines “common sense” as: “1. Native good judgment. 2. The set of generally unexamined assumptions as distinguished from specially acquired concepts.”

As my dictionary makes perfectly clear, the core concept is human judgment. My thesaurus agrees. Here are the first few synonyms for common sense it provides: “good sense, savvy, sound judgment, native intelligence.”

When the researchers discuss their methodology, however, it appears they neglect the core concept of common sense:

First, we talk about commonsensicality, which we define in a specific mathematical way, but intuitively captures how much agreement there is between people on a topic … Second, we talk about collective common sense, which we define as groups of shared belief between people and topics.

In fact, the two subjects they “talk about” seem more or less the same subject: “how much agreement there is between people on a topic” and “groups of shared belief between people and topics.”

In any case, having evidently skipped the dictionary’s first definition of common sense as something having to do with the human ability to make good judgments, the researchers then go on to offer claims that do not fit the second dictionary definition, either. It is not clear that the claims they put forth are “generally unexamined assumptions as distinguished from acquired concepts.”

Two certainly are not. “Triangles have three sides” is an excellent example of an acquired concept, acquired, in this case, from geometry. “Perception is the only source of knowledge, what is not perceived does not exist” is also an excellent example of an acquired concept; it is acquired from philosophy, specifically empiricism. Empiricism is one of a number of competing views in epistemology (the theory of knowledge). Its rivals include skepticism and rationalism, and, interestingly, the philosophical system that takes its name from common sense, commonsense realism.

In addition, a child with very little common sense might be able to learn that a triangle has three sides, and a person with very robust common sense—my grandmother, for example—might not have been able to make heads or tails of the principle of perception from the philosophy of empiricism. Neither the claim from geometry nor the claim from empiricism is an example of the kinds of assumptions we can say human beings share owing to common sense.

Examples of those common sense assumptions do abound, however. In fact, the fundamental assumptions we agree on because of the common sense we share are infinite in number. Our agreement on those fundamental assumptions is shown in the number of things human beings do and what we refrain from doing. For example, we don’t let infants play with sharp knives; it’s just common sense, as we would say. But we do help children learn to handle knives safely as they grow up. And we do not jump off tall buildings holding onto an umbrella expecting to test whether doing so will get us safely to the ground—not if we have common sense. And so on ad infinitum we can count such examples.

Common sense is the thing that enables us to size things up, to make judgments about what works, what does not work, what is good, what is safe, and so on. We all possess it to some degree: the wise to a greater degree, the young and the foolish to a lesser degree.

A deep exploration of common sense reveals that it is the power of judgment that enables us to be rational creatures and moral agents. But all that takes us far beyond the reach of the approach taken in the research reviewed in Newsweek for reasons that, if you have common sense, are probably not so difficult to decipher.