Sarah Glenn

Not long after the special theory of relativity was published in 1905, the French physicist Paul Langevin first formulated one of the best-known implications of the theory, the twin paradox.  If one twin could be sent to a nearby star at a speed approaching the speed of light while the other twin remained on earth, a strange thing would happen: the twin who traveled to the star would, on his return to earth, find that his brother was either very aged or even dead.[1] Special relativity explains that this occurs because time does not move at the same rate for both twins.  If two people or things do not share a frame of reference, time does not progress at the same rate for them.  Instead, the rate of passage of time is relative to frame of reference.  It was this implication of relativity that drew the strongest criticism.  Its opponents feared what might follow from the idea that time is relative to frame of reference.  After all, if time—one of the fundamental irreducible quantities of physics—varied with frame of reference, less fundamental aspects of reality must also be subject to variation, and the objective basis of science would be lost.  One critic, for example, suggested that special relativity rejected science established on objective experiment “in favor of psychological speculations and fantastic dreams about the universe.”[2] Another was opposed to special relativity because its proponents “deny that any concrete experience underlies these [mathematical] symbols, thus replacing an objective by a subjective universe.”[3] In short, what they feared was that relativity, if established, would lead to epistemological relativism.

Relativism threatens to undermine the basis of science and of objective knowledge in general.  The different kinds of relativism (ethical, epistemological, cultural, aesthetic) focus on different aspects of a thing, but they share in common the belief that some aspect of a thing is as it is only with respect to frame of reference.  There are things to recommend this idea.  We know, for example, that frame of reference affects perception.  We also know that the reality of a thing is rarely as simple as it appears to be from any one frame of reference.  These two things taken together suggest that the truth of a thing is never exhausted by what is revealed in a single frame of reference.  Instead, different—perhaps even contrary—truths are revealed from different perspectives.  The flexibility of such relativism is appealing because it both allows for and explains the perspectival nature of truth.  But it also has a serious weakness since this view suggests that there is no objective basis of knowledge.  If what is seen from each frame of reference is true in it and no one frame of reference is privileged to call itself the right one, knowledge is always conditioned by one’s viewpoint, that is, it becomes subjective, as the second critic quoted above feared.  Perhaps even more importantly, its extreme forms suggest that not only is there no objective basis but that we are all trapped in our subjective viewpoints, unable to leave our own frame of reference to see what anyone else sees.  We can never understand reality as understood from other perspectives because we quite literally cannot see from another point of view.  As a result, there is no way of resolving conflicts between the truths of different perspectives or of ascertaining any more about reality than what one’s own frame of reference reveals.

But Einstein’s relativity is not relativism.  He acknowledges the significance of frame of reference; indeed, frame of reference is so critical that it even determines the rate of passage of time.  It genuinely determines at least part of the truth.  However, had his critics considered his work more carefully, they would have realized that acknowledging the role played by frame of reference is not the same as advocating some form of relativism.  Quite the contrary: relativity is founded on a principle which is not compatible with relativism.  According to Einstein, the principle of relativity the restricted sense states that, for two systems K and K’ in uniform motion relative to one another, “Relative to K’ the mechanical laws of Galilei-Newton hold good exactly as they do with respect to K.”[4] In other words, the laws of nature that apply in one system (or frame of reference) apply and apply in the same way in all others.  This is the opposite of relativism at least insofar as it insists that some things hold in all frames of reference. Light, for example, travels at the same speed in all frames of reference.  Einstein later reinforces this point in his discussion of general relativity when he insists “the laws [of nature] themselves must be quite independent of the choice”[5] of frame of reference.  Einstein’s adherence to this principle does lead to the conclusion that the passage of time differs with frame of reference, but this difference is attributable to the fact that all frames of reference obey the same laws, and this fact in turn makes it possible to determine how the passage of time differs between frames of reference.  In other words, Einstein’s theory recognizes real differences between systems, but it also believes that those differences can be understood and accounted for from any given frame of reference.  It provides truth with the flexibility that makes relativism so appealing but also allows us to bridge frames of reference in a way that extreme relativism denies is possible.

The philosophical relevance of relativity lies in its implications about truth in general.  Knowledge of reality, Einstein says, is not simple.  It is neither something universal nor something that is entirely determined by frame of reference.  Instead, truth is the result of the operation of laws within a particular context, and one cannot know truth without knowledge of both of the laws and the context.  This notion suggests that truth may be harder to ascertain since it is determined by two variables rather than one, but it also carries with it the advantage of acknowledging the role of perspective while allowing us to overcome its limits.

[1] I. Bernard Cohen, Revolution in Science (Cambridge, Massachusetts: The Belknap Press of Harvard University Press, 1985) 411-412.

[2] Cohen 376.

[3] Cohen 414.

[4] Albert Einstein, Relativity: The Special and the General Theory (New York: Three Rivers Press, 1961) 16.

[5] Einstein 110-111.

The members of the Philosophy Department were asked which book they thought would be important to teach to students in an introductory philosophy course. Their answers are below. You can listen to them all at once or you can click on the name of the individual professor below to listen to each professor’s answer.

All answers in one mp3 file.
click the link to play or right click to download.

-Professor Robert Anderson

David Hume-An Inquiry Concerning Human Understanding

-Professor Robert Augros

Professor Augros argued that the dialogue between teacher and student was more essential to the philosophical process than any book.

-Professor David Banach

Euclid’s Elements

Albert Camus- The Stranger

-Professor Montague Brown

Plato- The Republic

Online edition

Saint Augustine’s Confessions

Online edition

-Professor Drew Dalton

Marcus Aurelius-The Meditations

Online edition

Slavoj Zizek


-Father John Fortin

Saint Anselm- Monologium


-Professor Susan Gabriel

Bertrand Russell- The Problems of Philosophy

Online edition,M1

-Professor Sarah Glenn

Sophocles- Oedipus Rex

-Professor Matthew Konieczka

Leo Tolstoy-The Death of Ivan Ilyich

Plato- The Apology

Online Edition

-Professor Thomas Larson

Plato- The Republic

Online edition

-Professor Max Latona

Josef Pieper-The Philosophical Act

Professor James Mahoney
C.S. Pierce, “The Fixation of Belief”

Michael Novak, Belief and Unbelief

-Professor Joseph Spoerl

Plato- The Gorgias

Online edition

Plato- The Republic

Online edition

Plato- The Apology

Online Edition

-Professor Kevin Staley

Plato- The Euthyphro

Another semester teaching material I have taught for the last ten years . I was discussing Plato’s Apology with yet another introductory class: the reason Socrates asks questions, the difference between doxa and real knowledge, the reason he is wiser than others. I suspect that almost every intro philosophy class begins with this discussion. Why was I teaching it yet again?

In fact, it made me wonder why academics, even at prestigious research institutions, teach at all. Research is the main job of professors at many large universities, yet even these researchers are expected to teach. Why? One obvious answer is that these places still ostensibly exist for the purpose of educating people, so faculty must teach at least a few token classes to foster the image that the university serves the larger community. This is the cynical answer, and while there are undoubtedly those who believe it, I suspect that it is not the real reason teaching continues to be part of the duties of professor at research-centered schools.

Perhaps it is simply that these professors need to teach so that students are exposed to the ideas they develop in their research. What is the point of doing research, after all, if it is not publicized? This argument is even weaker than the first one, for teaching is hardly the best way to make one’s work known. Furthermore, it too is a rather cynical understanding of the reason for teaching: teaching does not serve the university’s interest in perpetuating its image as an institution of service, but rather it serves the individual faculty member’s interest in making himself known.

Reflection on this question led me, at least, to a rather different conclusion. Teaching is not something that is required of faculty because it justifies their salaries or because it allows them to indulge in sharing what they have learned. Both of these ideas presuppose that the faculty possess ideas that have value and that teaching allows them to in some sense share this value. I am not going to dispute the fact that these people have ideas worth sharing. However, it is not the reason professors are required to teach.

We are required to teach so that we constantly have to face questions about the value of our subject areas. This is most apparent to those who teach courses required of students majoring in other subjects. Many people dread these courses, for the students invariably want to know why they have to take them. This is the very question that many of us would not consider if we were not constantly challenged by it. Of course our subject area is important; it seems self-evident to us that it matters and that an educated person should know something about it. But what is the value of our discipline? Why does it matter? One very rarely finds professors asking each other these questions at conferences; indeed, there is a good chance that someone who did ask such a question would be ridiculed, because everyone believes his or her own area is interesting, if not important. Students—very often the ones we do not regard as “good ones”–force us to consider this question, though. They want to know why the material matters, or at least matters to us, and if we cannot provide them with an answer, then our understanding of what we profess to know is no more than the doxa Socrates criticized in his Apology.

The Meet the Philosopher Series are interviews with the members of the Saint Anselm College Philosophy Department. They aim at introducing you to the members of the department along with their interests and ideas. Professor Sarah Glenn is the thirteenth profile in the series.

In this interview, Professor Glenn talks about how she became interested in philosophy, her interest in science, and her work on the problem of parts and wholes.

Saint Anselm Philosophy Podcasts can be found here.

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