Philosophy and Common Sense

By Jonathan Dolhenty, Ph.D.

As with the term “philosophy” itself, we can assign both a broad general meaning and a strict technical meaning to the expression “common sense.”

In its wide, popular meaning “common sense” is simply the conglomeration of generally held opinions and beliefs, more or less well founded, more or less mixed up with error and prejudice, which make up the voice of the community — “what everybody knows.” It may also refer in this broad usage to good practical sense in everyday affairs — to “good horse sense.”

In a philosophical context the expression has had a number of meanings. For the Romans, common sense meant the vulgar opinions of mankind. For Thomas Aquinas it was a technical expression for the unifying sense (“central” sense). For certain modern philosophers it has meant a kind of “instinct” or “special feeling” for the truth (this seems to be the doctrine held by Thomas Reid and the “Common Sense” Scottish School of thought).

None of these usages square with the strict interpretation that modern-day classical philosophic realists (including the school of “Contextual Realism”) have given to the expression “common sense” above. It is important, therefore, to realize the exact sense in which it is used.

Common sense refers to the spontaneous activity of the intellect, the way in which it operates of its own native vigor before it has been given any special training. It implies man’s native capacity to know the most fundamental aspects of reality, in particular, the existence of things (including our own existence), the first principles of being (identity, noncontradiction, and excluded middle), and secondary principles which flow immediately from the self-evident principles (causality, sufficient reason, etc.).

One of the points that links philosophy and common sense is that they both use these principles. They differ however in the way they use them. Common sense uses them unconsciously, unreflectively, uncritically. They can be obscured or deformed for common sense by faulty education, by cultural prejudices, by deceptive sense imagery. Philosophy, on the contrary, uses these principles critically, consciously, scientifically. Philosophy can therefore defend and communicate its knowledge.

The certainties of common sense, the insights of a reasoning which is implicit rather than explicit, are just as well founded as the certainties of philosophy, for the light of common sense is fundamentally the same as that of philosophy: the natural light of the intellect. But in common sense this light does not return upon itself by critical reflection, is not perfected by scientific reasoning. Philosophy, therefore, as contrasted with common sense is scientific knowledge; knowledge, that is, through causes.

A second point which links philosophy and common sense is that they take all of reality for their province — common sense blindly, in a kind of instinctive response of the individual to the totality of experience; philosophy consciously, in the endeavor to give every aspect of reality its due.

This claim of philosophy to know the whole reality does not mean that the philosopher makes pretense of knowing everything — the human intellect cannot exhaust the mystery of the smallest being in the universe, let alone everything. It remains true, nevertheless, that all things are the subject matter of philosophy, in the sense that the philosopher takes as his angle of vision or point of view the highest principles, the ultimate causes, of all reality. Along with common sense, then, philosophy seeks the comprehensive, all-inclusive view of reality; it is the knowledge of all things.

Philosophy is thus close to common sense and at the same time different from it. It differs from common sense because it holds its conclusions scientifically (that is, intellectually, rationally, and through causes), with a clarity and depth inaccessible to common sense. It is close to common sense because it shares the universality of common sense and a common insight into the fundamental structure of reality.

We might even say that philosophy grows out of common sense, and that common sense taken in its strict meaning is a kind of foreshadowing, a dim silhouette, of philosophy proper. Any philosophy, therefore, that strays very far from common sense is suspect. If it goes so far as to contradict the basic certitudes of common sense, then it is guilty of denying reality itself, and on this point common sense can pass judgment on it.

Keep in mind this point which is clearly stated on our homepage regarding the position of classical philosophic realism as interpreted by The Radical Academy:

“The Radical Academy is an analysis of the human condition as seen through the eyes of an authentic philosophical realism fundamentally grounded on the judgments of common sense, critically examined and expanded.”

Notice the phrase “common sense, critically examined and expanded.” This means that our common sense judgments must be subjected to a critical examination; sometimes our common sense beliefs are wrong and can be corrected by reflection upon them. (The exceptions here, of course, are the spontaneous convictions regarding the existence of objects — including ourselves — and the truth of the self-evident principles.)

Furthermore, the “Contextual Realist” adds the addendum “and expanded,” because Contextual Realism supports the “possibility” of multiple universes, parallel universes, a multidimensional reality, extrasensory perception, and so on, speculations that go beyond common sense and may, in fact, contradict common sense beliefs. This is one reason why Contextual Realism as a philosophy is very comfortable with the findings and speculations of modern quantum physics, many of whose propositions are obviously contrary to common sense, and also with the findings and speculations of parapsychology, many of whose propositions are contrary to the “conventional wisdom.”


Dr. Jonathan Dolhenty was the Founder and President of The Center for Applied Philosophy and the Radical Academy, and is Honorary Philosophy Editor at The Moral Liberal. The Moral Liberal has adopted these projects beginning with a republishing and preserving of all of Dr. Dolhenty’s work.