PHI 313 HW 8

Pre-precept submission due: [2017-11-20 Mon] 11am. Pre-precept submission form.

HW due: [2017-11-21 Tue] 2pm. Note that this homework is due Tuesday rather than Wednesday. Homework submission form

(Reminder: getting in the assignment and also a good-faith pre-precept attempt on time is a precondition for getting a “K” on the assignment.)

1 Instructions

Please name each homework map you create as follows: “hwK-mapN, where K is the homework number and N is the map number within that homework.

2 Tasks

Create and map an argument for skepticism about the past (SP), the claim that no one is justified in believing any propositions about the past. (Propositions about the past are propositions such as “yesterday I had eggs for breakfast”, “the Earth is more than 1000 years old”, and so on.) Hint: one good way to proceed is to start with one of the BIV arguments we’ve studied, and adapt it to the case of skepticism about the past. If you do this, it may help to think of a hypothesis about the past that is analogous to the brain-in-a-vat hypothesis. Your map needn’t be very elaborate, and it is ok if you don’t at the end of the day accept all of its premises. Just make it as strong as you can.
Map one candidate paper idea. That is: choose an argument map you have made or gotten in the class. Make a copy of it using “File > make a copy”. Add your idea to the map, clearly marking what is the new contribution. For example, if your contribution is an argument against one of the map’s claims, add that argument to the map as an objection.
[Optional] Call the argument you created in part (1) above “Argument M”. Now map the following argument, intended to stop anyone from finding Argument M convincing:¹

It is irrational to be persuaded by Argument M. Here is why. Suppose that someone—call him “Dion”— has been persuaded by Argument M. In other words, Dion believes SP on the basis of Argument M. I will now argue that Dion is irrational.

Dion believes SP on the basis of Argument M. But he himself must think he is not justified in believing SP. And it is irrational to believe something while believing that one is not justified in believing it.

Why must Dion think he is not justified in believing SP? Because Argument M is a reasonably complex argument. So Dion realizes that he cannot hold all of its steps in his head at one time. So in coming to believe SP on the basis of Argument M, Dion must at some point rely on his memory. But Dion now believes SP, and so believes that no one is ever justified in relying on their memory.

Footnotes:

The argument is (very loosely) based on an argument due to Susanna Rinard.