In this second part of my case against 100% certainty, I tackle claims to logical certainty. These include appeals to the three fundamental laws of logic: the Law of Excluded Middle, the Law of Non-Contradiction, and the Law of Identity. To call excluded middle into doubt, I discuss non-referring terms, vagueness, fuzzy logic, and Aristotle’s problem of future contingents. For contradiction, the topics are legal contradictions, the Liar paradox, and Zeno’s Arrow. To argue against certainty of the law of identity, I cover Theseus’s ship, problems with time, problems of mereology, and the universe of symmetrical spheres. I then argue that even claims like “2+2=4” and “bachelors are bachelors” can’t be fully foolproof. Finally, a quick barrage of skeptical concerns – concerns that, while they may not be enough to justify a self-defeating view like skepticism, are enough to block claims to 100% certainty.
0:20 – Quick pt. 1 recap
1:21 – Introducing claims to logical certainty
2:21 – Classical logic, syllogistic logic, and the 3 laws
5:48 – Law of Excluded Middle
6:45 – Non-referring terms: the present king of France
9:16 – Vagueness and fuzzy logic
12:11 – Future contingents
13:51 – Law of Non-Contradiction – DeMorgan’s Law
15:38 – The legal case
18:22 – Liar paradox
22:09 – Zeno’s arrow
26:45 – Law of Identity – Theseus’s ship
29:26 – Content of an instant
31:17 – Mereological – Tibbles
36:06 – Symmetrical spheres
37:47 – Do we understand identity?
In this interview with epistemologist Jim Slagle, we discuss the Epistemological Skyhook. That is, the argument that certain philosophical positions (such as naturalism and determinism) give us a reason to believe in skepticism, which in turn, gives us a reason to doubt the reasoning that got us to the position in the first place. If the argument is correct, then while it is possible that naturalism or determinism might be true, it is impossible for us to believe in them. In this first part of our two-part discussion, we focus on Alvin Plantinga’s version of the argument.
I was staring at a fireplace listening to music. I had the following progression of thoughts:
The bass line in this song is really awesome.
It’s a very active bass line. I don’t know much about music and almost nothing about good bass playing. Any active bass line is going to sound good to me.
Does that mean that, since I don’t know much about music, none of my opinions about music matter?
I have strong opinions about music. Favorite albums, artists, songs, instrumentalists. To someone who knows a lot about music, those opinions must seem superficial and misguided.
This is true even if we agree that taste is subjective. Even among matters of subjective taste, some taste is refined and some misses all the nuances of the form. Some is based on understanding the medium and some is based on irrelevant associations.
Does this mean that all of our opinions about subjects in which we are not experts are misguided?
Actually, even if we’re experts, we can always assume that there’s another expert who knows the subject more, or we can imagine one in the future who will. That person’s opinion is based on more and better evidence than mine. Shouldn’t I just automatically adopt his position?
Does this mean we shouldn’t believe any of our beliefs? Should we assume all our beliefs are wrong? Should we just believe what the most knowledgeable expert beliefs?
My train of thought took me to radical skepticism, as they often do.…