PHIL 160: Why Do We Believe in Quarks, Evolution, and Other “Crazy” Things? Professor: Lynn Hankinson Nelson Instructors: Tyrel Mears Jon Rosenberg

PHIL 160: Introduction to Philosophy of Science Course website: Course description and requirements Course topics and reading schedule, with links to electronic readings Assignments, including on line quizzes for weeks 1-3

PHIL 160: Introduction to Philosophy of Science Philosophy of science: “Science is just refined common sense and philosophy of science is just science gone self-conscious” W.V. Quine What is science? How is it different, if it is, from other enterprises or institutions (fiction? art? religion? politics?) What is its impact, historically and currently – on our beliefs? lives? What impact, if any, do our “social beliefs and values” have on science?

PHIL 160 What is the nature of the evidence that supports scientific hypotheses and/or theories? How strong is that evidence? Suppose a theory includes objects (such as quarks) or historical events/processes (such as evolutionary events/processes) that are not directly observable? What kind of evidence supports such theories and the objects/processes they posit? What does it mean to say that something (e.g., evolutionary theory) is “just a theory”?

PHIL 160 What is science? Some proposed answers:  A body of knowledge (theories and hypotheses) that grows cumulatively and progressively  Ancient astronomy → Ptolemaic/Aristotelian astronomy → Copernican/Galilean astronomy  A specific method (or set of methods) that distinguishes it from other enterprises or activities (including others concerned to gain or produce knowledge)  Facts → Hypothesis → Testing → Theory  Problem → Hypothesis → Testing → Adjusting or abandoning the hypothesis…

PHIL 160 What is science?  A social institution that, like others, includes goals and norms, divisions in labor and authority, prestige hierarchies, competition, rewards…  And that interacts with other social institutions (economic or industrial institutions, political institutions, military institutions…)  And that enjoys a high degree (perhaps the highest amount) of cognitive authority.  We take scientists’ theories within the field of their expertise to be “definitive knowledge”.

PHIL 160 All of these are compatible with: Science is an enterprise concerned to develop theories that explain and predict phenomena When did it emerge? Origin myths Of political systems Of a people and their culture In general, origin myths reflect what some system or people or institution values and take to be unique

PHIL 160 When did science emerge? Myths as “proto” science Vegetation myths: Why are there seasons? Demeter, Persephone, and Hades An explanation of the changes in seasons And, as such, allowing for predictions of future phenomena How are myths different from science, if they are – and if they are, when did (genuine) science emerge?

PHIL 160  On some accounts, something like science emerged among the ancient Greeks in Miletus around 650 BCE.  There a group began to ask: What is everything made of and how does the answer to this question explain nature, including change?  The one and many  Thales: Everything is made of water  Anaximander: Everything is made of “the boundless”  Anaximenes: Everything is made of air  Democritus: Everything is made of a-toms

PHIL 160  The one and many  Appearance and reality  It doesn’t appear that everything is made of one kind of stuff  Contemporary particle physics and String Theory:  What are the ultimate building blocks of the universe?  Natural explanations of phenomena  We’ve moved beyond appeal to supernatural entities and processes  Critical evaluation of such explanations  Moving beyond appeal to the supernatural, we are in a position to critically evaluate explanations

PHIL 160  An alternative account of the emergence of science:  The Scientific Revolution  When the Copernican hypothesis, the heliocentric view of the (then known) universe eventually (and through Galileo’s efforts), succeeded in replacing the geocentric view advanced by Ptolemy and Aristotle  As the Ptolemaic/Aristotelian view had been accepted by the Catholic Church as “divinely revealed”, and because Galileo was condemned as a heretic and confined to house arrest for life, this episode is often taken to represent  The victory of science (evidence-based theorizing and knowledge) over religion (faith, dogma…)

PHIL 160  This origin story has had legs…  It embraces a dichotomy between science and faith (or religion)  It is one of several episodes (Darwin being another) in which religious views were appealed to in the rejection of a scientific theory.  It has served to underwrite (justify) two norms: 1.That knowledge is a good in itself. 2.That science must be autonomous: that science must be able to proceed with finding out how things are without interference based on religious views or other forms of social resistance based on values.

PHIL 160  This origin story has had legs…  But, like many (if not all) origin myths, it is far from fully accurate and self-serving  There were good scientific reasons to doubt the Copernican hypothesis and the observations made possible by Galileo’s telescope  Many of those in the Catholic clergy who opposed the Copernican hypothesis were actually scientists, and their objections were scientific in nature.

PHIL 160 Terminology Epistemology: theory of knowledge What is the source, what are the limits (if any) of our knowledge? any) of our knowledge? Specific to science: how are theories generated, how/why are they accepted, what are their limits? And what is the nature and strength of the evidence for our current theories? Metaphysics: what there is What do our current scientific theories assume there is? What do they assume about nature What evidence is there for such views?

PHIL 160 Terminology Logic: The study of inferential relationships Inference: Moving from (reasoning from) one claim or set of claims to another Examples: 1. Drug X has no harmful effects on rats 2. Rats and humans are in relevant and significant ways similar So, probably Drug X will have no harmful effects on humans

PHIL 160 Logic: In relation to science: What (if anything) is the “logic of discovery” -- what kind of inferences lead to the discovery of hypotheses or theories What is the logic of “justification” (or testing) – what kinds of inferences do scientists make when testing a hypothesis or theory?

PHIL 160 A key notion: an argument An argument is a set of sentences (at least two), one of which is a claim being argued for (the conclusion) and the other or others of which are offered as reasons (or premises) to support it. Many of the scientists and philosophers we will read offer arguments for the claims they make. There are good arguments and bad arguments, and good arguments for false claims as well as bad arguments for true claims.

PHIL 160 Leon Lederman Nobel laureate in physics An experimental physicist in the area of particle physics and former director of Fermilab The God Particle: If the Universe is the Answer, What is the Question? Still pursuing the question that interested the ancient Greeks: what are the ultimate building blocks of the universe? And addressing the question: what is the evidence for “un- observable” objects, events, and/or processes? (Pay particular attention to “the invisible soccer ball”!)