# PHIL102: Logic and Critical Thinking

Unit 6: Scientific Reasoning   Unlike the syllogistic arguments we discussed in the last unit, which are a form of deductive argument, scientific reasoning is empirical.  This means that it depends on observation and evidence, not logical principles.  Although some principles of deductive reasoning do apply in science, such as the principle of contradiction, scientific arguments are almost always inductive.  Instead of truth and falsity, science deals in confirmation and disconfirmation.  Nonetheless, there are very specific rules about what constitutes good scientific reasoning, and scientists are trained to be critical of their own inferences as well as those of others in the scientific community.  In this unit, we will investigate the standard method of scientific reasoning, the characteristics of good and bad scientific explanations, the principles of confirmation and disconfirmation, and the challenges of reasoning about one of the most important scientific concepts, namely causality.

This unit should take you approximately 5.75 hours.
☐    Subunit 6.1: 1.75 hours

☐    Subunit 6.2: 4 hours

☐    Subunit 6.2.1: 0.5 hours

☐    Subunit 6.2.2: 1 hour

☐    Subunit 6.2.3: 0.5 hours

☐    Subunit 6.2.4: 0.5 hours

☐    Subunit 6.2.5: 0.5 hours

☐    Subunit 6.2.6: 0.5 hours

☐    Subunit 6.2.7: 0.5 hours

Unit6 Learning Outcomes
Upon successful completion of this unit, you will be able to: - describe and illustrate the hypothetical-deductive method; - identify some implications of the hypothetical-deductive method for testing scientific hypotheses; - describe the difference between the terms theory and evidence; - describe the method of Ockham’s Razor, and identify some implications of this method; - describe and contrast some criteria scientists use to choose among competing hypotheses; - contrast and illustrate several different notions of causation; - describe, illustrate, and compare the so-called Mill’s methods for reasoning about causation; - describe and contrast different kinds of causal relations; - describe and illustrate the difference between correlation and causation; - describe and contrast different visualization tools for representing causal relations; and - describe and illustrate several fallacies pertinent to reasoning about causation.

6.1 Basic Principles of Scientific Reasoning   6.1.1 The Method of Scientific Reasoning   - Reading: University of Hong Kong’s Critical Thinking Web: Joe Lau and Jonathan Chan’s Scientific Methodology: “Tutorial S01 and Tutorial S02” Link: University of Hong Kong’s Critical Thinking Web: Joe Lau and Jonathan Chan’s Scientific Methodology: “Tutorial S01 and Tutorial S02” (HTML)

Instructions: Read these two tutorials on scientific reasoning. Science itself is almost infinitely varied, but its basic method is surprisingly simple. These tutorials will introduce you to the four components of the hypothetical-deductive method and the difference between truth and confirmation.

Reading these tutorials should take approximately 30 minutes.

`````` Terms of Use: This resource is licensed under a [Creative Commons
attributed to Joe Lau and Jonathan Chan, and the original version
can be found [here](http://philosophy.hku.hk/think/).
``````

6.1.2 The Scientific Method, Explained by a Scientist   - Lecture: YouTube: Ask a Physicist’s “Episode 8, Part 1 – The Scientific Method” and “Episode 8, Part 2 – The Scientific Method” Link: YouTube: Ask a Physicist’s “Episode 8, Part 1 – The Scientific Method” (YouTube) and “Episode 8, Part 2 – The Scientific Method” (YouTube)

Instructions: Watch both of these videos. Pay particular attention to the discussion of the difference between the terms theory and evidence, as well as the discussion of the reasoning method called Ockham’s Razor.

Watching these videos and pausing to take notes should take approximately 30 minutes.

`````` Terms of Use: Please respect the copyright and terms of use
displayed on the webpages above.
``````

6.1.3 What Makes One Scientific Theory Better than Another   - Reading: University of Hong Kong’s Critical Thinking Web: Joe Lau and Jonathan Chan’s Scientific Methodology: “Tutorial S03” Link: University of Hong Kong’s Critical Thinking Web: Joe Lau and Jonathan Chan’s Scientific Methodology: “Tutorial S03” (HTML)

`````` Instructions: Read this tutorial on theory choice. In scientific
practice, multiple theories will frequently be put forward to
explain the same phenomena. When this happens, scientists sometimes
use five criteria to guide their decisions among alternative
theories.

Reading this tutorial should take approximately 15 minutes.

attributed to Joe Lau and Jonathan Chan, and the original version
can be found [here](http://philosophy.hku.hk/think/).
``````

6.1.4 Review of Basic Principles of Scientific Reasoning   - Reading: The Saylor Foundation’s “PHIL102 Discussion Forum” Link: The Saylor Foundation’s “PHIL102 Discussion Forum” (HTML)

Instructions: Consider the following prompts. Share your thoughts on the discussion forum by clicking on the link above and creating a free account, if you have not already done so. Review and respond to at least one or two other students’ posts.

1.   Given what you know about criteria for theory choice in science, such as predictive power, mechanism, fruitfulness, simplicity, and coherence, is there anything other than evidence that scientists use in determining whether to accept a theory? Should there be?
2.   Are simpler theories more likely to be true? Is Ockham’s Razor always a good rule of scientific reasoning?

Completing this activity should take approximately 30 minutes.

6.2 The Question of Causality   6.2.1 Causality Basics   - Reading: University of Hong Kong’s Critical Thinking Web: Joe Lau and Jonathan Chan’s Scientific Methodology: “Tutorial S04” Link: University of Hong Kong’s Critical Thinking Web: Joe Lau and Jonathan Chan’s Scientific Methodology: “Tutorial S04” (HTML)

Instructions: Read this tutorial, which outlines some important terminological distinctions for dealing with causation.

Causation is an ideal topic to address in a course on critical thinking, because it is something we feel we understand well in our everyday lives. Once we begin trying to think scientifically about causes, however, we find that fixing the causes of some event requires precision and subtlety.

Reading this tutorial should take approximately 30 minutes.

`````` Terms of Use: This resource is licensed under a [Creative Commons
attributed to Joe Lau and Jonathan Chan, and the original version
can be found [here](http://philosophy.hku.hk/think/).
``````

6.2.2 Five Ways to Identify a Cause   - Reading: University of Hong Kong’s Critical Thinking Web: Joe Lau and Jonathan Chan’s Scientific Methodology: “Tutorial S05” Link: University of Hong Kong’s Critical Thinking Web: Joe Lau and Jonathan Chan’s Scientific Methodology: “Tutorial S05” (HTML)

`````` Instructions: Read this tutorial about Mill’s five methods for
identifying causes. The 19<sup>th</sup>-century English philosopher,
John Stuart Mill, proposed five distinct ways in which a cause might
be identified through observation. While these methods may appear to
be very close to common sense, it is important to see that they
represent distinct modes of inference.

Reading this tutorial should take approximately 1 hour.

attributed to Joe Lau and Jonathan Chan, and the original version
can be found [here](http://philosophy.hku.hk/think/).
``````

6.2.3 Causality is More Than Just Cause and Effect   - Reading: University of Hong Kong’s Critical Thinking Web: Joe Lau and Jonathan Chan’s Scientific Methodology: “Tutorial S06” Link: University of Hong Kong’s Critical Thinking Web: Joe Lau and Jonathan Chan’s Scientific Methodology“Tutorial S06” (HTML)

This tutorial identifies seven different types of causal relations. Each type of relation is followed by a set of defining criteria. Although each type of relation is a cause-and-effect relationship between A and B, information about the context of the interaction and the relation of A and B to one another in time affects what we can say about the causal relation between them.

Reading this tutorial should take approximately 30 minutes.

`````` Terms of Use: This resource is licensed under a [Creative Commons
attributed to Joe Lau and Jonathan Chan, and the original version
can be found [here](http://philosophy.hku.hk/think/).
``````

6.2.4 The Difference between Causation and Correlation   - Reading: Carson-Newman College: Dr. L. Kip Wheeler’s “Correlation and Causation” Link: Carson-Newman College: Dr. L. Kip Wheeler’s “Correlation and Causation” (HTML)

Instructions: Read this example-rich tutorial, which explains the difference between the two relationships of correlation and causation. Scientists looking for cause-and-effect relationships in the natural world need to be careful not to misconstrue causality with mere correlation.

Reading this tutorial should take approximately 30 minutes.

6.2.5 Ways of Representing Cause and Effect   - Reading: University of Hong Kong’s Critical Thinking Web: Joe Lau and Jonathan Chan’s Scientific Methodology: “Tutorial S07” Link: University of Hong Kong’s Critical Thinking Web: Joe Lau and Jonathan Chan’s Scientific Methodology: “Tutorial S07” (HTML)

`````` Instructions: Read this tutorial illustrating two ways of
diagramming cause-and-effect. Notice that they allow for the
description of multiple causes and effects from a single event as
well as for distinguishing between levels of causation.

When multiple relations of cause and effect are involved in the
behavior of some phenomenon, representing these relations visually
is often the best way to get a handle on them and to assist in
quantitative analysis of the system in question.

Reading this tutorial should take approximately 30 minutes.

attributed to Joe Lau and Jonathan Chan, and the original version
can be found [here](http://philosophy.hku.hk/think/).
``````

6.2.6 Fallacies about Causation   - Reading: University of Hong Kong’s Critical Thinking Web: Joe Lau and Jonathan Chan’s Scientific Methodology: “Tutorial S08” Link: University of Hong Kong’s Critical Thinking Web: Joe Lau and Jonathan Chan’s Scientific Methodology: “Tutorial S08” (HTML)

Instructions: Familiarize yourself with this brief list of fallacies associated with causation. You should recognize some of these from unit 3.

Reading this tutorial should take approximately 30 minutes.

`````` Terms of Use: This resource is licensed under a [Creative Commons
attributed to Joe Lau and Jonathan Chan, and the original version
can be found [here](http://philosophy.hku.hk/think/).
``````

6.2.7 Review of Causation   - Activity: The Saylor Foundation’s “PHIL102 Discussion Forum” Link: The Saylor Foundation’s“PHIL102 Discussion Forum” (HTML)

Instructions: The following passage is an extract from a report by Arizona Daily Wildcat (June 16, 1999) concerning a study to show that certain people can communicate with the dead. Using what you have learned about causation, correlation, and causal fallacies, consider the potential flaws with the experiment. Assume that the report is mostly correct. Summarize your evaluation of the flaws in the experiment, and share your thoughts on the discussion forum by clicking on the link above and creating a free account, if you have not already done so. Review and respond to at least one or two other students’ posts.

``````Gary Schwartz, psychology professor and co-founder of the University
of Arizona Human Energy Systems Lab speaks about his work at the
University of Arizona (UA). A team of UA scientists and students
conducted a unique experiment this weekend, probing the possibility
of an afterlife by studying how mediums commune with the dead.

Researchers invited a panel of mediums to meet with 10 people whose
loved ones recently died. The mediums tried to receive information
from the deceased without prior knowledge about the deceased and
while under observation.

Schwartz invited four mediums to participate in the study,
including famous “superstars” of the psychic world, such as author
John Edwards, and unknowns, such as California housewife Laurie
Campbell. The medium sat facing a wall while a researcher looked on.
A “sitter,” who had recently lost a relative or friend, would then
enter the room and sit six feet behind the medium. Schwartz
acknowledged that a few of the sitters were acquaintances of the
mediums.
For up to 10 minutes, the medium and the sitter would sit in
silence. The medium, who could not see the sitter, would concentrate
on receiving psychic impressions. A question and answer session
followed, in which the sitter was allowed only to answer “yes” or
“no.”

Schwartz said that the study was set up to minimize communication
between the medium and the sitter, avoiding conscious or
subconscious prompting between the two. While the final results have
not been written up, Schwartz said he was impressed with the
mediums’ performance. On several occasions the mediums were able to
pick out the names and personal information of the deceased, he
said.

Completing this activity should take approximately 30 minutes.

University of Hong Kong’s [Critical Thinking
Web](http://philosophy.hku.hk/think/critical/improve.php), which is
attributed to Joe Lau and Jonathan Chan, and the original version
can be found [here](http://philosophy.hku.hk/think/). <span
id="cke_bm_555S" style="display: none;">“Gary Schwartz, psychology
professor and co-founder of the University of Arizona Human Energy
Systems Lab speaks about his work at the University of Arizona (UA).
A team of UA scientists and students conducted a unique experiment
this weekend, probing the possibility of an afterlife by studying
how mediums commune with the dead.

Researchers invited a panel of mediums to meet with 10 people whose
loved ones recently died. The mediums tried to receive information
from the deceased without prior knowledge about the deceased and
while under observation.

Schwartz invited four mediums to participate in the study,
including famous “superstars” of the psychic world, such as author
John Edwards, and unknowns, such as California housewife Laurie
Campbell. The medium sat facing a wall while a researcher looked on.
A “sitter,” who had recently lost a relative or friend, would then
enter the room and sit six feet behind the medium. Schwartz
acknowledged that a few of the sitters were acquaintances of the
mediums.
For up to 10 minutes, the medium and the sitter would sit in
silence. The medium, who could not see the sitter, would concentrate
on receiving psychic impressions. A question and answer session
followed, in which the sitter was allowed only to answer “yes” or
“no.”

Schwartz said that the study was set up to minimize communication
between the medium and the sitter, avoiding conscious or
subconscious prompting between the two. While the final results have
not been written up, Schwartz said he was impressed with the
mediums’ performance. On several occasions the mediums were able to
pick out the names and personal information of the deceased, he
said.”<span id="cke_bm_555E" style="display: none;"> </span>

Completing this activity should take approximately 30 minutes.