Truth tables for quantified statements

Today we had a very interesting discussion following our attempt to do problem number 10 on page 446 in Stan Baronett's Logic. In doing the proof it looked like we might have a typo in the conclusion. To check this and see if the argument was invalid (which it looked like considering the conclusion was a conjunction of Aa and not Ha with EG applied to it, but Aa would have to be entered into the proof via Addition. Only DeMorgan's would enable us to change it. But after multiple approaches none seemed to work. So we attempted to do a truth table to check it. It was at that point I realized I have never seen a truth table applied to quantified statements before - they are not truth functional? Here is one explanation I found: (from http://williamstarr.net/teaching/2310/10.20-4up.pdf) Truth tables work by explaining the truth of a complex formula in terms of the truth of its parts Example: :P is t i P is f The problem with using truth tables for quantifi ers is that the truth of quantifi ed formulas cannot be determined from the truth of its parts Example: 8x Cube(x) is t i ??? Cube(x) is t? f? Neither! Cube(x) isn't capable of truth or falsity, it's too incomplete! So, we can't use truth tables to explain what quantifi ed sentences mean But see the link and following discussion of Tarski's World. What helped was removing the quantifiers and doing the table for instances of the statements. Doing that it became obvious that the argument was invalid by that truth table.

Doing exercises in Stan Baronett's Logic I did a truth table for problem 30 page 409 and the argument is invalid - for table with P = T, and Q R S all F, the premises are true but the conclusion false.

It is that time of the logic course where we cover fallacies and I always use this time to also talk about humor. The main reason is that talking about humor means playing some hilarious videos which main class more enjoyable. But it also brings up a very interesting point - and very real point - that jokes seem to be invalid arguments. So what we can do is look at the varieties of fallacies and compare them to the varieties of jokes to see if the templates behind the fallacies are similar to those that seem to structure the jokes. Keep in mind that behind this whole exercise is making the point that the structure of fallacies / jokes might be entertaining but what makes the structure funny is at the same time what makes the structure a poor way to frame an argument.

Intro to Logic class start

Beginning the second five week session of the summer today! Intro to Logic met for 2 hours and looks like it will be a fun group. So far I have been using the video camera to record the lecture and they are posted on my Youtube page here:

Okay, so here we have Ellen doing a show: http://www.youtube.com/watch?v=5V5IzWgZzcY and here we have Robin doing a show: I find both are funny but I can really only watch Ellen because of the vocabulary. Robin uses vocabulary that makes me feel - uncomfortable. Why does he have to do that? Can't he be as funny as Ellen without it?

Trying to keep up with the wave

We have had a real dose of summer this year! Several days of above record temperatures - to accompany above record swarms of mosquitoes. Chocolate is soft. People are complaining that it is too warm! Imagine!? Meanwhile, my reading and courses continue with all sorts of interesting things going on. Who said philosophy is old? New books in my awareness include Daniel Dennett, Thomas Metzinger, and Douglas Hofstadter, as well as a host of others. So this summer I have moved away from the Zizek, Badiou connection to try to keep up with the wave of more analytic philosophy with an emphasis on the mind and language. This certainly ties in with Zizek and Badiou, but the language is easier to follow. I have to admit one of Thomas Metzinger's youtube videos was a challenge to follow since it was in German and fast. It also included more humor than I recall hearing in a German lecture - ever. Since his English is so good, I wonder if English style humor is a characteristic that can bleed over into German speech? Check it yourself: http://www.youtube.com/watch?v=N1MBG7FaZKM Okay, so the first was a mistake and occurs just at the end of the first segment. He misquotes the famous line from the Tractatus. "Wowon man nicht sprechen kann, daruber muss man schweigen." Thomas accidentally says "sprechen" instead of "schweigen" - so "speak" instead of "be silent". Obviously the audience laughs when they catch it and Thomas becomes instantly funny in response. Of course much of the reaction I interpret as humor is actually a response to some unusual things he says, as that religion and spirituality are not related! He is using spirituality more along the lines that William James does in "The Varieties of the Religious Experience".

Summer!

Well, summer has arrived. I am convinced. We have not put our plants in the ground yet but today or tomorrow we will start. I have been watering the "lawn". Only one course has started since one of my two online courses had low enrollment and so I elected to change it to a five week course starting the second session. So far it still has low enrollment so please encourage folks interested in taking Intro to Philosophy to sign up for section PHIL_A201_592_51962. I am also looking forward to moving my office to Eagle River this summer so I am ready for Fall courses at the UAA building in Eagle River. I will be teaching three sections for the Alaska Middle College School. This should also mean I will be walking to work! I will still have one section at UAA main campus on Monday evening. So far this summer I have been trying to catch up on my reading. All of those books I checked out this Spring I am going through bit by bit and posting my thoughts on my Amazon Vine page. So I split my time from reading in the office and reading on the back deck at home. My hope is to stay a fluent speaker of many disciplines.