"Polling as Pedagogy" in a Metaphysics Course

I was impressed with Thomas and Eddy’s paper, “Polling as Pedagogy.”  So this summer when I was putting together a metaphysics course for the fall, I decided to incorporate some of their suggestions into the course.  Seven weeks of the semester are structured in the following manner.  On Monday, I administer, collect, and discuss a survey on a topic in metaphysics that we would be examining that week.  Wednesday’s class focuses on discussing the related chapter or chapters from the primary text for the course (E. J. Lowe’s A Survey of Metaphysics).  Friday’s class is devoted to a primary reading related to the Lowe chapter(s) for that week.

Having done two of the surveys thus far, I am very pleased with the results.  As Thomas and Eddy note, this is a great way of fostering class discussion and understanding where our students are at in terms of their philosophical thought (e.g., I've caught a number of students in contradictions).  But there are already also some interesting results.  Here is the schedule from last week:

Week 2:  Change and Persistence

Monday                      Ship of Theseus survey

Wednesday               Lowe, chapter 2 “Identity over time and change of composition”

Friday                         Roderick Chisholm, “Identity through Time” (chapter III of Person and Object)

Here is the first part of the survey that I gave them last Monday:

Case:

In 100 BC, Theseus builds a ship made of wooden planks, possessing a very distinctive shape, whose sole purpose is to make a yearly voyage from

Athens

to

Sparta

to honor Achilles and Agamemnon.  Let us call this ship the Original Ship.  After a few years, the wooden planks begin to weather.  Theseus and his crew replace the weathered planks with new planks before each year’s voyage.  After ten years (90 BC), all of the ship’s original planks are replaced.  Let us call this ship the Continuous Ship.  The Continuous Ship has no planks in common with the Original Ship. 

However, unknown to Theseus, Glaucon is collecting the weathered planks Theseus is discarding.  At the end of the ten years, Glaucon has all the planks that made up the Original Ship.  Glaucon builds a ship, with the same shape as the Original Ship, composed of these planks.  Call this ship the Reconstructed Ship. 

While Theseus is sailing the Continuous Ship to

Sparta

, Glaucon sails the Reconstructed Ship to

Smyrna

. 

Question:

(1)   Which of the ships, if any, is numerically identical with the Original Ship?

____   Only the Continuous Ship.

____   Only the Reconstructed Ship.

____   Both the Continuous Ship and the Reconstructed Ship.

____   Neither; ships cannot survive a change in their parts.  As soon as Theseus replaced the first worn plank, the Original Ship ceased to exist.

____   Neither; ships do not exist.

____   Other.  Explain:

I was rather surprised to see that 14 out of the 29 students in the course selected the fourth option; this suggests that perhaps mereological essentialism is not as counterintuitive as many think. 

[7 students said that the Original ship is numerically identical with the Continuous Ship; only 1 student said the Original Ship was numerically identical with Reconstructed Ship; 3 students said both the Continuous Ship and the Reconstructed Ship were identical with the Original Ship; 1 student (who I know has already been exposed to Merrick’s argument for eliminativism folk ontology) denied the existence of ships; and 3 students said ‘other’.]

Comments

[Kevin Timpe]

Here is some more data from my survey on the ship of Theseus. After they had filled out the previous question, I gave them a second handout which contained the following information [which is adapted from Christopher Brown's "Aquinas And The Ship Of Theseus" (Continuum 2005):

----
Common Sense Intuitions:
A. There are compound material objects like ships (i.e., material objects that have parts, like the ship’s planks).
B. Compound material objects can survive the loss or replacement of some of their parts.
C. Two material objects cannot exist in the same place at the same time.
D. Numerical identity is transitive (if X = Y, and Y = Z, then X = Z).
E. One material object cannot be in two places at the same time.

The Problem:
These 5 common-sense intuitions lead to a contradiction:

1. The Original Ship in 100 BC is numerically identical with the set of original planks.
2. This same set of planks is numerically identical with the Reconstructed Ship in 90 BC.
3. Therefore, the Original Ship in 100 BC is numerically identical with the Reconstructed Ship in 90 BC.
4. The Original Ship in 100 BC is numerically identical with the Continuous Ship in 90 BC.
5. Therefore, the Continuous Ship in 90 BC is numerically identical with the Reconstructed Ship in 90 BC.
6. But the Continuous Ship in 90 BC cannot be numerically identical with the Reconstructed Ship in 90 BC.

Question:
(2) In order for your answer to question (1) to be true, which of the Common Sense Intuitions would you have to reject (i.e., believe to be false)?

Accept / Reject
____ / ____ A. There are compound material objects like ships.
____ / ____ B. Compound material objects can survive the loss or replacement of some of their parts.
____ / ____ C. Two material objects cannot exist in the same place at the same time.
____ / ____ D. Numerical identity is transitive (if X = Y, and Y = Z, then X = Z).
____ / ____ E. One material object cannot be in two places at the same time.

----
Students were also given space to elaborate on their answers if they so desired.

The follow-up question helped me understand not only why the students they gave for their first answers, but also to evaluate whether or not their thought was consistent. For example, the student who said that the Original Ship was numerically identical with the Continuous Ship indicated that he rejected B, the intuitive claim that compound material objects can survive the loss or replacement of some of their parts. In class discussion, the student said that the identity of compound material objects is a function of the totality of the parts they are composed of. Since the Reconstructed Ship in 90 BC was composed of all the same planks as the Original Ship in 100 BC, the student’s answer was internally consistent. Similarly, the student who claimed in question 1 that ships do not exist rightly indicated that he rejected common sense intuition A. Of the three students who claimed that both the Continuous Ship and the Reconstructed Ship are identical with the Original Ship, two denied that numerical identity is transitive while the third denied that two material objects cannot exist in the same place at the same time. Of the seven students who claimed that only the Continuous Ship was numerically identical with the Original Ship, six denied that numerical identity is transitive—thereby blocking the inference from 1 and 2 to 3 in the argument—while the seventh denied that one material object cannot be in two places at the same time. During the discussion period, this student came to realize that rejecting E is insufficient to show that only the Continuous Ship is identical with the Original Ship. Finally, of the fourteen students who appeared to accept mereological essentialism in response to question (1), all of them correctly noted that if order for it to be the case that ships cannot survive a change in their parts, they would have to reject common sense intuition B.

[Eddy Nahmias]

Hi Kevin,
Very cool survey and results. I especially like the way you follow up to try to engage the students to consider how their initial intuitions impact (or should impact) their acceptance and rejection of philosophical premises. Your students seem quite smart! Please keep us informed about other surveys and results you are using.

[Billie Pritchett]

Mr. Timpe:

I am interested in your surveys, and I find it great that you are approaching these metaphysical issues in this way. But I was curious if you had considered allowing your students to give these options a sort of 'credit rating.' That is, perhaps they are on the fence as to whether the Continuous Ship or the Reconstructed Ship is the actual ship. Or perhaps they do not know whether they are willing to admit ships into their ontology. In which case, they might be inclined to number the answers for likelihood 1, 2, and so on. What do you think? Anyway, I do think it's a wonderful idea, and I'd like to begin to think about how I would respond to some of these cases myself.

[Kevin Timpe]

Billie,

I decided to use a binary system on most of these surveys to force the students into taking a stand and see what follows from that stand. I think you're right that we can hold beliefs more or less firmly--and this often came out in the discussion. But I wanted to keep the survey as simple as possible. As it was, the discussion was so robust after giving them 10 minutes to take the survey that I had to cut off questions and comments at the end of the hour-long class.