Are Humans Rational?
(Singularly So!)

Table of Contents

Selmer Bringsjord & Atriya Sen




1 General Orientation

The Aristotelian dictum that we are rational animals is under severe attack these days. In fact, the previous sentence may be to seriously understate the situation: the dictum is perhaps outright rejected by many, if not most. From psychologists of reasoning and decision-making to behavioral economists to the “new atheists” (all groups whose message we will consider in this class), the onslaught is firmly underway, and fierce. Yet this course revolves around a defense of the proposition that Aristotle, modernized along Leibnizian, Piagetian, and Bringsjordian \(\times\) 2 lines, is right. This proposition, put a bit more precisely, is:

  1. \(\mathcal{R}\)

    Humans, at least neurobiologically normal ones, are fundamentally rational, where rationality is constituted by certain logico-mathematically based reasoning and decision-making in response to real-world stimuli, including stimuli given in the form of focused tests; but mere animals are not fundamentally rational, since, contra Darwin, their minds are fundamentally qualitatively inferior to the human mind. As to whether computing machines/robots are fundamentally rational, the answer is “No.” For starters, if \(x\) can’t read, write, and create, \(x\) can’t be rational; computing machines/robots can neither read nor write nor create; ergo, they aren’t fundamentally rational. But the news for non-human animals and computing machines/robots gets much worse, for they have not the slightest chance when they are measured against \(\mathcal{H}\), which runs as follows:

  2. \(\mathcal{H}\)

    Humans have the ability to gain knowledge by reasoning (e.g., deductively) quantificationally and recursively over abstract concepts, including abstract concepts of a highly expressive, including infinitary, nature, expressed in arbitrarily complex natural and formal languages.

  3. Rapid Example

    For a rapid example (provided long ago on Amtrak to Selmer by Professor Yingrui Yang, who relayed it from Professor Johnson-Laird) of some of the stimuli to which \(\mathcal{R}\) refers:

    1. Amtrak-to-Princeton J-L Problem

      Suppose that the following two statements are true:

      1. Everyone likes anyone who likes someone.
      2. Abigail likes Bruno.

      Does it follow deductively that everyone likes Bruno? Prove that your answer is right!

  4. Notice: ‘Fundamentally’

    Notice that the adverb ‘fundamentally’ is used repeatedly in \(\mathcal{R}\). This means, among other things, that humans are \emph{potentially} rational. What humans need in order to reason and make decisions in the relevant ways, we (i.e., SB & AB) further claim, is sustained study of the relevant logic and mathematics, and an ability to use what one has studied in order to reason and decide correctly in response to the aforementioned stimuli. In the course of our defense, we’re going to supply at least some of the relevant logic and mathematics to you. Hence, as you receive and judge our case, we believe that you will move some distance from being merely fundamentally rational to being presently rational. We believe it’s fair to say that the purpose of college is to markedly increase the level of reasoning and decision-making power that constitutes being presently rational.

  5. Context: A Research University

    You have wisely decided to attend a technical research university, with a faculty-led mission to create new knowledge and technology in collaboration with students. RPI is the oldest such place in the English-speaking world; it may know a thing or two about this mission. The mission drives those who teach you in this class. The last thing we want to do is simply convey to you how others answer the driving question that gives this class its name. As should be obvious by now, we think we have correct answers to the driving question, and are working hard to explain them, specify them formally, and disseminate them. We’ll tell you objectively what other thinkers say, but we’re going to tell you that, at least for the most part, they’re wrong. (As an immediate example, we hereby inform you that Ernest Sosa has long claimed that rationality should not be measured against formal logic; see his “Are Humans Rational?”, which we shall discuss in class.) You can judge whether our arguments are sound or not. And you should start to develop your own individual answer, which may well be different than ours. You should seek to defend your answer, and will indeed by asked to do so in this class. For purposes of evaluating your performance, it matters not a whit what your positions is; what matter is your understanding of the technical material presented, and the quality of your reasoning given in defense of your positions.

  6. A Disclaimer!

    Please note that guest lecturers other than A Bringsjord should not be assumed to have affirmed anything like the claims \(\mathcal{R}\) and \(\mathcal{H}\) issued above. This thus applies specifically to, in the 2018 edition of AHR?, co-instructor Dr Atriya Sen, TAs Shreyansh Nawlakha and Swapnil Khandekar, and any guests from the RAIR Lab who visit us to speak/demo. It also applies to those who have helped in the past editions; e.g. Dan Arista, Professors John Milanese and John Licato, Thomas Carter, etc. As to what these thinkers hold in connection with \(\mathcal{R}\), that is an open question. You are free to inquire.

  7. Graduate Teaching Assistants; Further Help

    The TAs for this course are: Shreyansh Nawlakha; email address:; and Swapnil Khandekar; email address: Shreyansh will hold office hours on xxx xxxx–xxxx at xxx, and by appointment. Swapnil will hold office hours on xxx xxxx–xxxx at xxx, and by appointment. Additional assistance will be provided by some RAIR-Lab researchers.

    Please note again A Disclaimer!.

  8. Prerequisites

    There are no formal prerequisites. However, this course covers parts of such things as formal deductive logic, formal probabilistic logic, game theory, etc. This implies that — for want of a better phrase — students are expected to have a degree of mathematical maturity. At RPI, this expectation is quite reasonable.

    To be a bit more specific, the logico-mathematics alluded to in claims \(\mathcal{R}\) and \(\mathcal{H}\) can be partitioned into three general areas: analysis and continuous mathematics (A1); deductive formalisms, systems, and techniques (A2); and inductive/statistical/probabilistic formalisms, systems, and techniques (A3). Because of the nature of RPI’s requirements for a BS, A1 is generally already covered in other classes (on the integral and differential calculus). The emphasis in the present class is on (introductory elements of) areas A2 and A3.

2 Texts/Readings

In-class lectures deliver crucial content. (Assuming that things go according to plan, all lectures will be recorded, and will be available for review to all students.) Attendance is required and note-taking is key. Sometimes slides will be distributed by email. Most readings will be electronic, and either distributed by email, or can be obtained by url. As a first example, students should read Nicholson Baker’s “The Wrong Answer” asap, since it (we claim) represents a stark example of an implicit denial of both \(\mathcal{R}\) and \(\mathcal{H}\). As to books, it’s required that students purchase and read Kahneman’s (2013) Thinking, Fast and Slow. It’s recommended that students read the available-online The Nature of Rationality by Robert Nozick; S Bringsjord will be drawing from this book at times (in ways that will be announced clearly).

  1. Additional Readings
    1. Supplements to A1 (Deductive Formalisms)
    2. On Self-Aware Robots
    3. Tests (including back ones); Study Aids
      1. Test 1, Fall 2016, with solutions, is provided here.
      2. As an aid to study, learning, self-diagnosis, the midterm from Fall 2014 is hereby provided.
      3. The solutions to Test 1 for Fall 2015 are provided here.
      4. Test 1B is available here.
      5. Test 2 is available here.
      6. A preliminary 2015 “superset” of Test 3 is available here.
      7. A preliminary 2016 “superset” of Test 3 is available here.
    4. Reading on the Bi-Pay Auction
    5. Supplemental Readings on The Meaning of Life
    6. Readings on The Singularity and the MiniMaxularity…
    7. Readings on the Chinese Room Argument
    8. Readings on The Paradoxes

      None of the readings listed here are required: the slides I provide (combined with in-class discussion) are self-contained. The readings here are partitioned into two categories: general background overview of some of the paradoxes we study in class (e.g., The Liar Paradox, The Knowability Paradox, The Lottery Paradox), and — for those who might be interested, or who in subsequent study in the future may want some things available at their fingertips — further reading that gets into details, and is more technical. Accordingly, here’s a list:

3 Syllabus

  • The Fall 2018 PDF version available here. Recall that the syllabus has hotlinks to some required reading!

4 Slide Decks

  1. August 30 2018: The syllabus was projected and presented, course overview, etc. (Selmer Bringsjord)
  2. September 6 2018: Setting the Stage; \(\mathcal{R}\) and \(\mathcal{H}\) Discussed (Selmer Bringsjord)
  3. September 10 2018: Some “Classic” Shots at Main Claim \(\mathcal{R}\) (Selmer Bringsjord)
  4. September 13 2018: Rational Analysis of Shots at Main Claim \(\mathcal{R}\) (Selmer Bringsjord)
  5. September 17 2018: “Cognitive” Deductive Shots @ \(\mathcal{R}\) (Selmer Bringsjord)
  6. September 20 2018: Re The Monty Hall Problem (Selmer Bringsjord)
  7. September 24 2018: Addenda to Prop Calc; The Case of Linda, & Probability (Atriya Sen)
  8. September 27 2018: Critique of Kahneman on Investing; Bi-Pay Auction; Re Test 1 (Selmer Bringsjord)
  9. October 1 2018: Test 1 (Selmer Bringsjord)
  10. October 4 2018: Rational Investigation of The Meaning (if any) of Life (Selmer Bringsjord)
  11. October 9 2018 The Singularity, Rationally Considered (Selmer Bringsjord)
  12. October 11 2018 The Future of AI: A Sober Assessment of Machine Learning (Atriya Sen)

    This class was a presentation and discussion that revolved around the 2018 paper “Do Machine-Learning Machines Learn?” by Bringsjord, S., Govindarajulu, N.S., Banerjee, S. & Hummel, J., which is in Müller, V., ed., Philosophy and Theory of Artificial Intelligence 2017 (Berlin, Germany: Springer SAPERE), pp. 136–157, Vol. 44 in the book series. The paper answers the question that is its title with a resounding No.

  13. October 15 2018 The MiniMaxularity & Human Disemployment (Atriya Sen & Selmer Bringsjord)
  14. October 18 2018 Logicist Machine Ethics Can Save Us (Selmer Bringsjord & Atriya Sen)
  15. October 22 2018: Rationality & Paradox, Part I: The Liar; The Barber; Dr Who Saves the Day; The Knowability Paradox (S Bringsjord)
  16. October 25 2018 Test 2
  17. October 29 2018: Newcomb’s Problem (Selmer Bringsjord & Atriya Sen)
  18. November 1 2018: Solving the Lottery Paradox — and the St Petersburg Paradox (Atriya Sen)
  19. November 5 2018 The Paradoxes of Time Travel (Atriya Sen)
  20. November 8 2018 Contra Darwin, Humans are Rational Animals, But Mere Animals are Not; and Darwin is Irrational in Thinking Otherwise (Selmer Bringsjord)
  21. November 12 2018: S Bringsjord on PHP’s BBS Paper “Darwin’s Mistake” (Selmer Bringsjord)
  22. November 15 2018: NLP: Animals, Machines, and Money [Selmer Bringsjord (with Rikhiya Ghosh)]
  23. November 19 2018 Informal Intro to Gold-style Learning, Extended; A RAIR-Lab Target
  24. November 26 2018: On “Breaking the Spell” of Irrationality; A Better Version of Pascal’s Wager (Selmer Bringsjord, Atriya Sen, Naveen Sundar G)
  25. November 29 2018: Steeple #1: Godel’s Completeness Theorem (Selmer Bringsjord)
  26. December 3 2018: Steeple #2: Godel’s Incompleteness Theorem (with: Can a machine match this?) (Selmer Bringsjord)
  27. December 6 2018: Steeple #3: Godel’s “Silver Blaze” Theorem (Selmer Bringsjord)

Author: Selmer Bringsjord

Created: 2018-12-07 Fri 11:45

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