The Philosophy of Physics
By: Oxford Academic
Tags: Oxford University Press, Physics, Philosophy, Science

In this excerpt from In Search of a Theory of Everything author Demetris Nicolaides discusses the importance of philosophy in physics.

Episteme means “knowledge” in Greek. For Aristotle, we have episteme if we know the cause of something.1 Science is episteme in Latin. Hence, strictly speaking, science includes all fields of knowledge (theology, philosophy, physics, history, etc.). Physics is a particular type of science: it is the study of physis (nature in Greek). With time, however, especially nowadays, the word science evolved to have a narrower focus, and it, too, means the study of nature. Because of this, physics and science have basically become synonymous, but also so because all subfields of science that study nature are really reducible to the natural laws of physics. For example, biology studies cells, which are made of molecules; chemistry studies molecules, which are made of atoms; and physics studies atoms. Therefore, generally all the sciences about physis are ultimately built from (and are branches of) physics.2 The natural philosophers3 of antiquity that we’ll consider were philosophers but also physicists. Philosophy and physics were then closely related fields.

According to legend, Pythagoras probably coined the term philosophy, “love of wisdom,” in Greek. So to define philosophy we need to know what wisdom is. Recall that the Oracle of Delphi prophesied that Socrates was the wisest, but he humbly doubted it.4 Using the art of dialectic (his famous questioning style, the maieutic), he set out to prove the Oracle wrong (by engaging in meaningful discussions with his fellow Athenians, politicians, poets, craftsmen, and farmers, in search of the truth) only to find out that the prophecy was spot- on. He was the wisest indeed for, unlike the others, who confused their skill with wisdom, their empeiria (in Greek, experience or talent) with episteme,5 he at least knew well one thing: that he knew nothing.6 Confessing ignorance gives healthy scepticism hope to advance to the truth and become wise. And the road toward wisdom begins for Socrates with the “know thyself,”7 by recognizing our mind’s limitations and the uncertainties of our methods of inquiry.

I’m not sure what wisdom might be, but I’m sure that the journey to it begins with a question and continues with courage, determination, and an honest effort to eliminate age- old, false beliefs and prejudices and seek rational (not dogmatic) answers.

I want to say, parenthetically, that knowing nothing is inconceivable. For the notion of “nothingness” is not allowed; it’s an impossibility!

Anyhow, I’m not sure what wisdom might be, but I’m sure that the journey to it begins with a question and continues with courage, determination, and an honest effort to eliminate age- old, false beliefs and prejudices and seek rational (not dogmatic) answers. Now, although we are born imaginative creatures with insatiable curiosity and desire for adventure and knowledge, with age we usually settle down both physically and mentally (our body and mind) and inquire less and less. Asking is a trait of youth but of philosophy, too. Neither solar nor entropic8 time ever ages the inquiring mind.

In a more concrete example, philosophy for me is this: I read a book about physics (of Albert Einstein, Steven Hawking, Michio Kaku), and I usually understand it well. Then I read a book about philosophy (of Aristotle, Bertrand Russell, Karl Popper), and I often don’t understand it that well. So then I reread it, and again, only to find out that I now understand better the physics book. And so sadly I keep on reaffirming that “the man of science is a poor philosopher.”9

Philosophia10 is She who managed to escape from the darkness of superstition and ignorance (from Plato’s cave) and dared to ascend into the world of light and knowledge. It is “the vision of truth,”11 it is the ability to “teach people to talk sense,”12 it is sameness in dissimilarity, or a subtle immutability in conspicuous change. It is part Apollo (reason) and part Dionysus (passion) but never any one alone, it “is something intermediate between theology and science,”13 or, put simply, philosophy might be what the Greeks called “the gift of wonder”14 — of imagining, searching, discovering, and learning all you can by wondering.

In the quest for truth about nature, science without (the wisdom of) philosophy is practical and rational but (arguably) dull, and philosophy without (the empirical facts of) science is abstract and wise but (experimentally) unverified.

Adding to such gift is science, the systematic study of nature and the organization of acquired knowledge into “timeless, universal,” causal, and, most important, testable laws that are derived from observation and rational consideration. A good scientific theory, therefore, makes experimentally verifiable and falsifiable predictions, which must be tested by experiment. Science is evidence based knowledge; it is not knowledge based on opinion or dogma. The defining characteristic of science is its unique way of study, the scientific method. It can be summarized in five steps.

(1) Observe nature. For example, things fall. (2) Formulate a question, a problem (based on observation). Why do things fall? (3) Answer the question with a hypothesis (an educated guess) that makes testable predictions (the cardinal rule of science). They fall because the earth is pulling them: dropped from rest, they should fall 4.9 meters in 1 second. (4) Perform properly designed reproducible experiments to collect data that will be used in order to verify or falsify the predictions of the hypothesis. Drop various objects from rest and measure the distance they fall in 1 second. (5) Draw conclusions by comparing the predictions of the hypothesis against the data of the experiment: (a) if the predictions are observed (i.e., they agree with the data, so things would indeed fall 4.9 meters in 1 second), the hypothesis is verified and it transitions into a scientific fact, a law of nature; (b) if the predictions are not observed (they are in disagreement with the data, things would not fall 4.9 meters in 1 second), the original hypothesis is falsified and thus replaced by a modified one or by something completely new.

This is the general scientific method as was formulated by philosopher Francis Bacon. A clarification: as Einstein, Popper, Richard Feynman, and Hawking argued, we can only verify a hypothesis; we can’t prove it — we can never be absolutely certain if the laws we discover are truly timeless and universal. For example, while experiment after experiment keep on verifying Einstein’s relativity, “No number of experiments can prove me right; a single experiment can prove me wrong,” said he.15 That is, a new type of experiment may find a flaw in the theory (not previously detected) that will prompt scientists to revise or completely change it with a new vision.

In the quest for truth about nature, science without (the wisdom of) philosophy is practical and rational but (arguably) dull, and philosophy without (the empirical facts of) science is abstract and wise but (experimentally) unverified.16 For Einstein, “science without epistemology is — in so far as it is thinkable at all — primitive and muddled.”17 The road to truth, I believe, is paved by science and philosophy, but certainly by other fields of knowledge, too. The view, otherwise, is of mere copies, shadows of truth.

In Plato’s parable of the cave,18 prisoners constrained in a cave since childhood and for many years thereafter can see only shadows and mistake these shadows for the only reality. The prisoners therefore are utterly ignorant of the objects that project the shadows. But the sight and insight of the prisoner who eventually manages to escape start to gradually improve. At last, outside the cave and in the light of the sun, she begins to have a better perception of reality. She now sees how things resemble their shadows, and she realizes that shadows are deceptive; they are only a mere copy of the real objects (and of the grander truth in general). Nature, she now knows, is much more than what She appears, but Her divine secrets can ultimately be untied by the curious, willing mind. Eager to share her newfound sense with her prisoner- friends, she descends once more into the cave. But passing suddenly into the darkness from the light makes her sight briefly feeble. Her friends are tricked by it and think, up she went with her eyes and down she came blind; thus, sadly, they believe that the cave is the only safe place.