Saturday, April 25, 2015

Top 5 reasons why people distrust science

When someone asks me why so many people, especially religious people, don’t believe what scientists tell us, it is too easy to say that people are ignorant or have one standard of evidence for soul-saving preachers and another for know-it-all scientists. There are better explanations.

1. Science is awesome.

The products of science are impressive, powerful, and dangerous. Scientific knowledge and understanding inspires technology. It gives us the World Wide Web, smartphones, supercomputers, spacecraft, robots, and weapons of mass destruction. Our lives are easier and more connected than those of our ancestors. Progress costs us much in privacy, security, and freedom. Medical innovations such as vaccines, antibiotics, pain-killers, contraceptives, anti-depressants, MRIs and mammograms extend our lives while making us more dependent upon them as nostrums and panaceas. Genetic engineering in plants and animals is remarkable but provokes neophobia and paranoia. What if its ubiquitous use threatens natural resource sustainability? Science enables people to do immoral things. Drones and clones are scary.

2. Science defies common-sense and challenges established world-views.

"Seeing is believing" but collective experience tells us not to believe everything we see. Common-sense says that whatever occurs happens for a reason, but physicists say otherwise. Modern physics finds that some events are uncaused when we can't help but think that every thing and every event has a cause. Subatomic particles can come into existence and perish by virtue of spontaneous energy fluctuations in a vacuum. Even the entire universe whose present form emerged in a cosmic explosion 13.7 billion years ago may not have had an ultimate or first cause. Some scientific models continue to suggest an eternal, cyclical, or oscillatory universe rather than a single creation event. Cosmologists say that the universe doesn't have a center and doesn't have an edge.

Science progresses by upsetting and superseding old world-views. Scholars in ancient and medieval times believed Earth was the fixed center of the cosmos, that there are only as many basic, unchanging kinds of organisms as God separately created, and that there are just four elements which comprise everything: earth, air, fire, water. But the history of science is a tale of numerous rejections of old beliefs. For almost 2000 years physicians practiced blood-letting, believing that good health required the delicate balance of bodily fluids: blood, yellow bile, phlegm, and black bile. Empirical observations revealed that bloodletting killed more people than it healed. Nobody still thinks disease is caused by angry gods or evil demons. We now treat mental illness without trepanations or exorcisms.

3. Scientists make contrary and even contradictory claims.

Researchers report that recent studies show low carbohydrate diets are healthier than low fat diets. If true, this contradicts established scientific findings and subsequent recommendations to reduce fats more than carbohydrates in one’s diet. They’ve reversed recommendations on salt and cholesterol intake as well. What are we supposed to believe when authorities change their minds?

Mainstream reports of science often distort the significance of some research, especially conclusions based on small samples or low quality, preliminary studies. Bad science makes headlines in part due to the politics of science itself. Often a specialist in one discipline, say, a cardiothoracic surgeon with a popular television show, becomes an authority on nutrition for the general public. Beware the authoritative non-expert. Physicians get the science wrong. Some doctors are scientists but most are not.

A “Referendum on Alcohol in the Practice of Medicine” prepared for the U.S. Congress in 1922 revealed that over 50% of physicians surveyed continued to prescribe “spiritus fermenti” or whisky, wine and beer as a necessary therapeutic agent for treating influenza, pneumonia, heart failure, shock, anemia, diabetes, cancer, asthma, dyspepsia, snakebite, lactation problems, and old age. So far no randomized controlled clinical trial (RCT) on even moderate alcohol consumption and mortality outcomes has been done. The medicinal benefits of alcohol have yet to be found. We must fact-check all sources of information, but when is the last time you looked at scientific literature?

4. Science is hard to do and assess, it is especially difficult for non-experts to understand.

The general public cannot easily check whether what scientist's assert is true. Scientists study complex, difficult to observe phenomena. They do so by drawing finer distinctions than common-sense and ordinary language permits. Without advanced training or at least a college course in inductive reasoning or statistics, most people who acquire a scientific conclusion from non-expert, second-hand sources cannot process it competently. We like stories not statistics. Ordinary people trust personal experiences and testimony but scientists rank types of evidence differently. In science any hypothesis is incredible if it cannot be falsified by experiment (i.e. tested with the possibility of being rejected).

Use science databases such as NCBI or PubMed. Do an online search with terms that narrow the field to higher quality sources, e.g. “low carbohydrate diet versus low fat diet meta-analysis randomized controlled”.

Here is rough guide to spotting bad science. Also, Trish Greenhalgh (1997) has a nice series of very short must read articles on "How To Read a Paper” that explain how to interpret different kinds of research papers.

5. Scientists doubt or reject what most people believe.

Most Americans believe in supernaturals (Harris Poll, 2013). People think that supernaturals explain events, but scientists don’t. Angels visit, ghosts haunt, devils make us sin, gods make and destroy worlds. For scientists, and methodological naturalists in general, supernaturals are superfluous. This is why so many are atheists (Pew Research, 2009). Science abjures faith and demands testable evidence. Its predictions are dire. All of this alienates scientists from non-scientists.

When beliefs are threatened by new facts, people grasp onto unfalsifiable justifications. Motivated reasoning and confirmation bias affects negatively our ability to evaluate scientific evidence. So when scientists tell us what we don’t want to hear we are dubious. We just don’t want to listen to people who are so negative all of the time.

Scott Merlino
Department of Philosophy
Sacramento State

Sunday, April 19, 2015

Do gays and lesbians have a constitutional right to marry?

Like most liberals, I strongly support the movement to legalize gay and lesbian marriage. But it is surprisingly difficult to discern what sort of argument the courts could use that would convincingly show that gays and lesbians have a constitutional right to marry. Most of the debate tends to focus on either of two distinct lines of argument.

The first is the “born that way” argument:
  1. A person’s sexual orientation is either inborn or fixed at an early age.
  2. It is wrong to criminalize behavior that a person does not choose to engage in.
  3. Therefore, gay/lesbian sex as well as marriage should neither be prohibited nor criminalized.
This argument is open to two serious objections.

(a) Although the first premise is widely believed to be true, it is in fact an empirical claim whose supposed truth is still vigorously debated among researchers.

(b) Even if premise 1 is true, the conclusion does not follow, for even if a person has a homosexual orientation, it does not follow that his or her sexual conduct must not be freely chosen. After all, many persons who are clearly heterosexual in orientation freely choose not to marry and/or engage in any sexual activity with persons of the opposite sex. Sexual orientation alone does not determine a person’s behavior.

The second argument maintains that laws prohibiting gay/lesbian sex or marriage are sexist and therefore in violation of the equal protection clause of the 14th Amendment.

This is a strange argument. Even if one grants that laws prohibiting gay/lesbian marriage are sexist because they deliberately deny lesbians the right to marry, states that have such laws (as well as the armed forces) have plausibly replied that the prohibition isn’t sexist because they apply to gay males as well as lesbian females. Such laws are really gender-neutral. Moreover, it is unwise to categorize such laws as sexist when it seems much closer to the truth to say they are motivated by homophobia, not sexism.

So what are the courts to do when called upon to decide the constitutionality of gay/lesbian marriage?

One possibility is they could, in effect, shift the burden of proof from the supporters of gay/lesbian marriage to the opponents. How so? They could require that the proponents of whatever anti-gay marriage law is before the court show that it satisfies the rational basis test, i.e., that the law satisfies some legitimate state purpose. This is a minimal requirement that any contested law must meet to qualify as valid law. But in this case, that wouldn’t be an easy thing to show. They can’t just say a majority of the public wants it that way, or that we have a long history of forbidding gay marriage, or that gays cannot be good parents of young children (empirically false), or that gay marriages threaten heterosexual marriages (patently false). I don’t know what they could say that would show a gay marriage ban serves a legitimate state purpose.

Clifford Anderson
Professor Emeritus
Department of Philosophy
Sacramento State

Thursday, April 16, 2015

What is naturalism?

The following is not a defense of naturalism, just a quick summary of the basic outlook and philosophical practice of naturalized philosophers, finishing with some standard criticisms and an indication of its current popularity. (Written for tonight's Philosophy Club discussion on naturalism at Professor Dowden's home.)

Naturalism and human knowledge 

Naturalism is associated with the rejection of First Philosophy (the idea that philosophical inquiry is logically prior to scientific inquiry, and that part of the task of philosophy is to determine the scope, limits, and proper method of the latter by a priori means.) Following Hume, naturalists tend to regard FP as historically unproductive and probably incoherent.  Naturalists tend to emphasize the fact that philosophers don't have special tools or methods unavailable to scientists. Hence, they tend to see philosophical knowledge and scientific knowledge as continuous rather than categorically distinct. Naturalists tend to approve of Otto Neurath's metaphor that "We are like sailors who on the open sea must reconstruct their ship but are never able to start afresh from the bottom." 

Naturalism and human understanding

Naturalists tend to think that improving our understanding of the world amounts to developing theories that provide better explanations of it, which at least partly means theories that improve our ability to predict and control the future. They tend to see this process as something that is inherently unkind to existing beliefs and intuitions. As such, naturalists tend to be very dubious about philosophical inquiries that begin with questions like "What is the nature of ___?" (where the blank is filled in with words like: knowledge, time, free will, self, goodness, etc.) and which proceed by exploring our ordinary intuitions about the meaning of these words.

Naturalism and human cognition

Naturalists take it as well-established that human beings are animals and that human knowledge and understanding is an evolved capacity. They believe our claims about the world have to be compatible with a scientific understanding of our perceptual and cognitive mechanisms (which of course is still in its infancy.) This, of course, means that naturalists reject supernatural knowledge and understanding. So, for example, the idea that some of our knowledge was simply revealed to us by a supernatural agent is a non starter from a naturalistic perspective.  In a similar vein, naturalists also reject the Cartesian and Platonic view that humans are born with ideas of divine origin.  (They do not reject innate ideas of evolutionary origin.) Naturalists also tend to reject the idea that there are categorically distinct realms of, say, moral, aesthetic, logical and mathematical knowledge, which can be apprehended in ways that aren't answerable to a scientific understanding of our perceptual and cognitive abilities.

Naturalism and the value of philosophical inquiry

Naturalism is not associated with a distinct view of the value of philosophical inquiry. Some naturalists, such as those who participate in experimental philosophy, see themselves as scientists who study questions that have been traditionally conceived as philosophical in nature. Generally speaking they deal with naturalized versions of these questions. For example, our newest faculty member Dan Weijers, is an experimental philosopher who does empirical research on happiness. Conceived as ethics, his work might be characterized as addressing a naturalized version of a traditional ethical question: What causes happiness and how can we make more of it? 

Other naturalistic philosophers see themselves as trying to make a distinct contribution to scientific problems at a conceptual level. They analyze scientific concepts and propose ways of improving them for scientific purposes. They also participate in the development of emerging conceptual frameworks, such as those that are currently being developed for scientific inquiry into consciousness, cognition, and communication. Often this involves explicating a term, the familiar meaning of which seems to be essentially supernatural or non natural, in a way that is susceptible to scientific inquiry. For example, the idea that personal identity consists in an unchanging 'self' that is the owner of its thoughts, feelings and body parts does not make sense in naturalistic terms. But there is little question that human beings have a distinct feeling of ownership and of being self aware, so the naturalistic project is to explicate a concept of self that will serve scientific inquiry into how and why this occurs.

Still other naturalistic philosophers explore the way that different areas of scientific inquiry are related and specifically how knowledge claims at different levels (e.g., physics, biology, psychology, sociology) are related. This approach is basically in accord with Wilfrid Sellars' view that philosophy is the study of "how things in the broadest possible sense of the term hang together in the broadest possible sense of the term."

Critical stances on naturalism

Most critiques of naturalism focus on naturalism as a prescriptive account about the right way to do philosophy. The main problem with prescribing naturalism to others is that it will typically seem to involve making the kind of a priori claims that naturalists themselves reject. For example, naturalists who insist that there is, and can be, no perspective outside of science from which to evaluate scientific knowledge and understanding may appear to need to inhabit that perspective in order to substantiate the claim.  Metaphysical naturalists who claim to know that there are no non-natural properties are susceptible to the same kind of criticism.

Naturalism may also appear to be self-defeating. Some, for example, believe that a fundamentally scientific perspective on human perception and cognition (specifically an evolutionary one that holds that our mental capacities evolved to serve the ends of survival, not truth) leads to the view that scientific knowledge is either not achievable or miraculous.

Naturalists also find it challenging to produce a compelling account of the nature of logical and mathematical knowledge, which may seem to entail the existence of abstract objects that we know by means that are inscrutable from a naturalistic perspective.

Naturalism as described here is not in any way committed to the so-called naturalistic fallacy or the is-ought fallacy. 

The current status of naturalism

According to a survey conducted by David Chalmers and David Bourget, about 50% of professional philosophers describe themselves as accepting or leaning toward naturalism, whereas about 26% accept or lean toward anti-naturalism. The remaining 24% declined to answer for one reason or another.

G. Randolph Mayes
Department of Philosophy
Sacramento State

Sunday, April 5, 2015

Aristotle and the infinite

The world envisioned by Aristotle contains the infinite. Let’s consider where and how. His world fits within a heavenly sphere, so every physical line is finitely long. So is every mathematical line. Aristotle’s reason is that the mathematicians’ diagrams used in his day always could fit on a piece of papyrus. Unfortunately, he was mistaken about what mathematicians required. Euclid’s fifth postulate, the axiom of parallel lines, contains the phrase “if extended indefinitely.” Later mathematicians understood this deficiency in the Aristotelian system and tried very hard, but unsuccessfully, to deduce the fifth postulate from the others.

Aristotle used two kinds of infinity. He explicitly denied the existence of the actual infinite both in the physical world and in mathematics, but he accepted the potential infinite in both realms. Forcing Zeno to say that Achilles’ path to catch the tortoise is potentially infinite but not actually infinite is Aristotle’s clever way out of Zeno’s Paradox. Unfortunately for Aristotle there is a more fruitful treatment of the paradox.

Aristotle’s chosen labels for kinds of infinity easily lead to misunderstanding. Potential infinities do not have the potential to become actual infinities. “Potential infinity” is Aristotle’s technical term that requires a repeatable, but incomplete, process. The term “actual infinite” does not imply being actual (i.e., real). It implies there is no dependency on some process in time. When Aristotle says something is infinite, he does not mean this infinity is merely possible. He means it is real or actual, but just not an actual infinity. Actual infinities are not actual. Potential infinities are actual, not potential. Thus the confusion.

Aristotle believed the sequence of natural numbers is potentially infinite in two different ways—by adding and by dividing. Regarding addition, numbers can be abstracted from existing objects and then a unit can be repeatedly added over time to the previous number. Yet at any time, there are only finitely many natural numbers produced by this or any other process. This reasoning also works for future time; for any day there is always tomorrow, or so Aristotle believed. The reasoning does not work for cows in the field; we cannot truly say there is always another cow.

The second way that the sequence of natural numbers is potentially infinite is based on the way that continuous magnitudes are potentially infinite. Given a specific continuous magnitude such as the distance between Achilles and the tortoise, it can be repeatedly split or divided, and one can count the number of its divisions so far. Yet it always could be divided again, thereby adding one to the count. It is in this second way that natural numbers are potentially infinite, Aristotle would say. Georg Cantor (1845-1918) would disagree and claim the natural numbers are an actual infinity. Cantor re-defined the term “potentially infinite” so that any potentially infinite set of numbers is a growing subset of a pre-existing actually infinite set of numbers.

There is more to be learned from examining the details of Aristotle’s notion of potential infinity. He says that what is infinitely divisible is continuous, but he does not believe that continuous magnitudes are divisible into indivisible points. Cantor does. Aristotle also believes that lines are not composed of points, although he believes there is an infinity of points on any line.

Consider Achilles’ continuous path in pursuit of a tortoise that is crawling away from him. What is the ontological status, for Aristotle, of the points where Achilles might be? The points where he stops are real because they are the end of a line and are independent of any activity by the analyst. The points where he merely might be are not independent of the analyst. They exist only in the derivative sense of being the product of a permanent possibility of division, and they do not exist independent of this division.

Zeno and 21st century realist philosophers would say instead that the points do exist independent of this division. Those philosophers infer from the fact that Achilles might stop at a point to there being this point where he might stop. Aristotle would not accept this inference. You can chase unicorns without there being unicorns you are chasing, he might say.

Aristotle probably would not have been happy with saying Achilles is always at some point or other. What then does Aristotle mean by saying Achilles runs past a potential infinity of points? The key idea is that, for Aristotle, a continuous line can be divided anywhere but not everywhere. Aristotle would say the line is not composed of a potential infinity of points, but rather it has a structure such that the analyst theoretically can imagine Achilles stopping somewhere new even if he does not actually stop there, and in that sense the analyst can create a new point along Achilles’ path, and either of those newly created sub-paths on each side of the point can in turn be subdivided by yet another point, and so on.

However, the line is potentially infinite only because there exists a theoretical division of the line, not a practical one, since the analyst cannot live long enough nor engage in the mental effort to have Achilles arrive at a new point for every old point, Aristotle would say. At any moment in the analyst’s theoretical division, there always will be unactualized potential future divisions. Having a new analyst pick up the job left incomplete by the first analyst would not change this result. So, the potential infinity of Achilles’ path does not depend upon any unending process existing. It is enough that the theoretical division exists.

One last comment on Aristotle and infinity. He never thought of infinity as having a measure or number. Archimedes (287-212 B.C.E.) was the first person to do this. In the Archimedes Palimpsest, he argued that the number of lines inside a rectangle is equal to the number of triangles inside a prism. Unfortunately, there is no evidence that he paused to explore these numbers.

Brad Dowden
Department of Philosophy
Sacramento State