Kevin Zollman
LightNews LightNews
banner
kevinzollman.com
Kevin Zollman
@kevinzollman.com
7.7K followers 1.7K following 5.6K posts
Philosophy and Game Theory at Carnegie Mellon 🦚 Research the interface between philosophy, economics, and biology 💱 www.kevinzollman.com
Posts Replies Media Videos
kevinzollman.com
Avery Brooks or gtfo
Avery Brooks looking cooler then every other star trek actor combined
November 20, 2025 at 5:12 PM
kevinzollman.com
Although occasionally Friedman draws on Popper, denying that theories can be confirmed. Carnap and Reichenbach would certainly have disagreed with this statement.
Viewed as a body of substantive hypotheses, theory is to be judged by its predictivepowerfor theclassofphenomena which it is intended to "explain." Only factual evidence can show whether it is "right" or "wrong" or, better, tentatively «accepted" as valid or "rejected. As I Shal] argue at greater length below, the only relevant test Of the udidiry of a hypothesis is comparison Of its predictions with experience. The hypothesis is rejected if its predic- tions are contradicted f "frequently» or morc often than predictions from an alternative hypothesis); it is accepted if its predictions arc not contradicted; great onfidence is attached to it if it has survived many opportunities for contradiction. Factual evidence can never "prove" a hypothesis; it can only fail to disprove it, which is what we generally mean when we say, somewhat inexactly, that the hypothesis has bccn "confirmed* by experience.
November 20, 2025 at 3:16 PM
kevinzollman.com
Friedman explicitly references the value of consistency and completeness results... although what he says makes me wonder if he really understands what that means. (What does "completeness" have to do with "rightness" and "wrongness" or intersubjective agreement?)
The answers to these questions depend partly on logical, partly on fac-tual, considerations. The canons of formal logic alone can show whether a particular language is complete and consistent, that is, whether propo-sitions in the language are "right" or "wrong." Pactual evidence alone can show whether the categories of the "analytical filing system° have a mean-ingful empirical counterpart, that is, whether they are useful in analyzing a particular class of concrete problems.' The simple example of "supply" and "demand" illustrates both this point and the preceding fist of analogical questions. Viewed as elements of the language of economic theory, these are the two major categories into which factors affecting the relative prices of products or factors of production are classified. The usefulness of the Logical completeness and consistency are relevant but play a subsidiary role; their function is to assure that the hypothesis says what it is intended to say and does so alike for all users — they play the same role here as checks for arithmetical accuracy do in statistical computations.
November 20, 2025 at 3:16 PM
kevinzollman.com
Here's Carnap saying basically the same thing in 1937:
• Logic is not concerned with human behavior in the same sense that physiology, psychology, and social sciences are concerned with It. These sciences formulate laws t univrsal statements which have as their subject matter human activities as processes time.e Logic, on the contrary, is concerned with relations between factual sentences (or thoughts). If logic ever discusses the truth of factual sentences it does so only conditionally, somewhat as follows: if such-and-such a sentence is true, then such-and-such another sentence is true. Logic itself does not decide whether the first sentence is true, but surrenders that question to one or the other of the empirical sciences.
November 20, 2025 at 3:16 PM
kevinzollman.com
Friedman argues that tautologies (like mathematical theorems) are valuable in helping define he language, but that empirical content is ultimately what determines the value of a theory.
But economic theory must be more than a structure of tautologies if it is to be able to predict and not merely describe the consequences of actions if it is to be something different from disguised mathematic '° And the usefulness of the tautologies themselves ultimately depends, as noted above, on the acceptability of the substantive hypotheses that suggest the particular categories into which they organize the refractory empirical phenomena.
November 20, 2025 at 3:16 PM
kevinzollman.com
The value of logic for making ideas precise was one of the central tenets of logical positivism and was common to all of them. Carnap describes this process as "explication"

iep.utm.edu/explicat/
The task of making more exact a vague or not quite exact concept used in everyday life or in an earlier stage of scientific or logical development, or rather of replacing it by a newly constructed, more exact concept, belongs among the most important tasks of logical analysis and logical construction. We call this the task of explicating, or of giving an explication for the earlier concept; this earlier concept, or sometimes the term used for it, is called the explicandum, and the new concept, or its term, is called an explicatum of the old one.
November 20, 2025 at 3:16 PM
kevinzollman.com
In the next paragraph of his essay, Friedman says the value of defining theory in terms of language is its ability to help us classify reality in ways helpful to designing successful theories.
Viewed as a language, theory has no substantive content; it is a set of tautologies. Its function is to serve as a filing system for organizing empirical material and facilitating our understanding of if and the criteria by which it is to be judged are those appropriate to a filing system. Are the categories clearly and precisely defined? Are they exhaustive? Do we know where to file each individual item, or is them considerable ambiguity? Is the system of headings and subheadings so designed that we can quickly find an item we want, or must we hunt from place to place? Are the items we shall want to consider jointly filed together? Does the filing system avoid elaborate cross-references?
November 20, 2025 at 3:16 PM
kevinzollman.com
Here Friedman explicitly describes a theory as a "language." And the scientific content as those claims which are not tautologies in that language.
The ultimate goal of a positive science is the developing of a "theory" or "hypothesis" that yields valid and meaningful (i.e. not truistic) predictions about phenomena not yet observed. Such a theory is, in general, a complex intermixture of two elements. In part, it is a "language: designed to promote "systematic and organized methods of reasoning" In part it is a body of substantive hypotheses designed to abstract essential features of complex reality.
November 20, 2025 at 3:16 PM
kevinzollman.com
This is my new favorite graph
A histogram with the face of Beethoven pointing at a location on the x-axis
November 13, 2025 at 1:26 PM
kevinzollman.com
Did my civic duty.

Then I ate a croissant.
A sticker with an outline of the Pittsburgh sky line. It says "I voted, n'at!
November 4, 2025 at 1:17 PM
kevinzollman.com
Bluesky, I walk by this sign everyday. Would you like to guess how many children I have seen playing there?
A small yard sign that says "please keep dogs off grass, kids play here!"
October 27, 2025 at 12:39 PM
kevinzollman.com
They also get their own signs
A picture of a blue sign that says "wombat poo" in front of a lake and a tree
October 10, 2025 at 12:46 PM
kevinzollman.com
George Berkeley laser eyes
October 9, 2025 at 9:00 PM
kevinzollman.com
October 6, 2025 at 8:53 PM
kevinzollman.com
Not more deadly than coconuts... yet.
A screenshot of the Wikipedia article entitled "death by coconut" It contains a warning sign of people running away from a coconut tree that appear to be throwing coconuts at them. The sign is written English and Japanese
September 30, 2025 at 1:46 PM
kevinzollman.com
I have heard about this issue for some time. I had an undergraduate professor and a colleague (now sadly died) from Argentina, and both reported their frustration with this fact to me.

I think the value of having a lingua franca is probably worth it, but it's also good to acknowledge the loss.
Text: A Lingering Loss Surprisingly, almost 90% of NNES respondents also said that frequent use of English in academia had interfered with their ability to do philosophy in their own language. I (Uwe) can relate. I’m a German (originally from East Berlin). After almost a decade of doing philosophy in English-speaking countries (e.g., New Zealand, Canada, the UK), I now struggle to explain my research in German. All I know in philosophy is ‘encoded’ in English in my mind. When German-speaking colleagues ask what I work on, I often freeze because I don’t know how to say it in German. Reaching a certain NNES proficiency may come at the cost of fluency in one’s native language—a loss that may be subtle but deeply felt.
September 24, 2025 at 2:23 PM
kevinzollman.com
Bust of Zeno with laser eyes
September 19, 2025 at 11:43 AM
kevinzollman.com
Meanwhile, in economics
Text: Fourth, the homogeneous commodities used in the experiment were 12 1982 Ben Oglivie Topps baseball cards, on which I had artfully drawn a mustache, make the cards valueless.
September 17, 2025 at 1:33 PM
kevinzollman.com
August 31st / September 1st
Younger Picard playing the recorder Old Picard wearing a hat from the inner light episode
August 31, 2025 at 12:47 PM
kevinzollman.com
August 25, 2025 at 8:33 PM
kevinzollman.com
That might be better than the alternative:
July 30, 2025 at 6:55 PM
kevinzollman.com
Btw, the study itself even found that 10,000 was actually good
For example, achieving 10 000 steps per day was associated with 10% lower risk of all-cause mortality compared with 7000 steps per day (appendix p 82). However, it is worth noting that for the rest of the outcomes, namely cardiovascular disease mortality, cancer incidence, type 2 diabetes, and falls, step counts beyond 7000 steps per day did not show statistically significant differences in risk reduction compared with 7000 steps per day (appendix p 82
July 24, 2025 at 10:12 PM
kevinzollman.com
Here's one that's about correct. It gets some things wrong, imo, because it forces the boundaries to be state boundaries
A map of regions of the US
July 20, 2025 at 8:15 AM
kevinzollman.com
Authentic Pittsburgh tacos
A picture of a sandwich from primantis in Pittsburgh. It contains tomato, coleslaw, meat, cheese and French fries
July 19, 2025 at 1:29 PM
kevinzollman.com
Authentic French tacos
The front of a business with the sign "Tactac taco's Authentic French tacos"
July 19, 2025 at 12:57 PM