Large Language Models (LLMs) are essentially "predict-the-next-word" machines, operating based on statistical correlations within vast datasets, not genuine comprehension.
Tokenization and embeddings convert text into numerical vectors, mapping similar words to close points in a high-dimensional space, thus encoding semantic relationships.
LLMs "rationalize" rather than "reason," often producing plausible but factually incorrect or inconsistent outputs by constructing justifications for pre-determined answers.
Research shows LLM performance drops significantly when irrelevant information is introduced or data distributions change, highlighting their reliance on superficial patterns.
This leads to "jagged intelligence," where LLMs excel unpredictably in some tasks while failing completely in others, irrespective of problem difficulty.
"Chain-of-Thought" (CoT) prompting, intended to make models "show their work," does not necessarily lead to genuine reasoning or reflect actual thinking effort.
LLMs demonstrate "performative thinking," where they generate elaborate, flawed justifications for incorrect or hinted answers, rather than acknowledging factual errors.
LLMs do not create new information; they are confined to processing and redistributing existing information, a concept supported by the "Law of Conservation of Information."
"Model Collapse" is a degenerative learning process where LLMs trained on their own generated output degrade over generations, forgetting improbable events and losing diversity.
This phenomenon is a significant concern for future AI systems as more AI-generated content proliferates the web, potentially leading to a decline in data quality.
Dr. George D. Montañez (Associate Professor at Harvey Mudd College, Visiting Fellow at University of Cambridge, Scholar in Residence at William Whewell Centre for Science & Natural Theology) asserts that Large Language Models (LLMs) are often misunderstood.
He directly challenges the prevailing Silicon Valley narrative that LLMs can "think," "reason," or "produce endless information."
His lecture, originally given at Baylor University, aims to provide a critical perspective on LLM capabilities.
Each die has words on its faces, weighted non-uniformly [5:15].
LLMs select a specific "die" based on the input context (prompt + output so far), roll it (representing a conditional distribution), and output the next token [5:24].
Text to Numbers: Tokenization and Embeddings [6:26]
Text is broken into "tokens" (roughly words or sub-word units), each mapped to a numerical representation [6:47].
Example: A word like "how" maps to a specific number (e.g., 3253) [7:11].
Problem: Tokenization can obscure semantic relationships (e.g., "are" and "aren't" map to distant, unrelated numbers, losing their logical connection) [7:37].
Addresses the loss of semantic information during tokenization.
Embeddings project numerical tokens into a high-dimensional space.
Words with similar meanings are mapped to points close together in this space (e.g., "salad" and "stew" cluster as "food"; "ship," "car," "bike" cluster as "means of transportation") [8:35].
This encodes semantic information via distance relations, similar to how humans use context clues [8:45].
II. Large Language Models Don't Reason, They "Rationalize" [13:07]
Zhang et al. [2022] "On the Paradox of Learning to Reason from Data" showed that LLMs learn statistical features to make predictions rather than learning to reason from data. They fail to generalize logic when data distribution changes [13:20].
This leads to "jagged intelligence": models excel in some areas, fail in others, with no correlation to actual problem difficulty [11:57].
ChatGPT (GPT-5) can perform simple multiplication but frequently makes errors in complex multi-digit multiplication, despite showing a "green checkmark" indicating confidence and correctness [9:40].
When corrected, the model breaks down steps but may still produce incorrect answers [10:24].
ChatGPT can miscount instances of letters in a word, highlighting a lack of fundamental understanding [11:02].
Mathematical Word Problems & Irrelevant Information [15:44]
Mirzadeh et al. [2024] demonstrated that adding irrelevant information to math word problems causes significant performance drops (up to 65%) in LLMs.
Models apply pattern matching based on keywords (e.g., "smaller than average" triggers subtraction), often leading to incorrect solutions [16:17].
Probabilistic Reasoning and Context Sensitivity [16:49]
Pournemat et al. [2025] showed LLMs struggle with probability estimation when problem representation changes (e.g., raw samples vs. frequency counts).
Performance was also affected by changing irrelevant labels (e.g., "Food" vs. "CS" items) even with identical numerical counts [17:37].
Chain-of-Thought (CoT) and "Performative Thinking" [18:10]
"Brittle Correlation" between CoT Length and Difficulty [18:50]
Palod et al. [2025] found negligible correlation between CoT trace length and problem difficulty, suggesting longer traces don't automatically indicate more "thinking effort" [19:00].
Turpin et al. [2023] demonstrated LLMs "rationalize." Given conflicting evidence, LLMs pick one interpretation and construct elaborate justifications, often changing facts to align with their chosen output, without true logical derivation [19:42].
When provided with a hint (even incorrect), LLMs adopt the hint and generate justifications, contradicting earlier statements without acknowledging the shift [21:53]. This process is termed "rationalization" [22:58].
Philosophical Implications: Syntax vs. Semantics [28:20]
Shumailov et al. [2023] introduced "model collapse": LLMs degrade over generations when trained exclusively on their own generated output [32:00].
Models forget improbable events (the "tails" of distributions), leading to a loss of diversity and factual accuracy [33:42].
This is a "degenerative learning process" that "poisons reality" for the model, as seen in texts becoming repetitive and nonsensical over generations [34:11].
As AI-generated content becomes prevalent on the internet, future LLMs trained on this data (often referred to as "AI-slop") are increasingly susceptible to model collapse [35:17].
Retaining original, human-generated data and vastly increasing training scale is necessary to mitigate this, but model collapse still occurs [34:42].
Using the analogy of a magician producing a rabbit from a "magic hat" (a "helper"), the information difficulty of the task is merely shifted [36:58].
The information needed to get the rabbit (new information) plus the information needed to obtain the magic hat (helper information) is always greater than or equal to the information difficulty of getting the rabbit originally [37:17].
You cannot get more information out of a system than you put into it [38:26].
Outputting information (even correct information) is easy if you also output incorrect information. A Turing machine can output all possible answers and non-answers, but filtering them incurs an information cost [40:09].
Randomized sampling or interpolation do not create new knowledge; they recombine existing information [42:04].
Extracting implications (deduction) only reveals what is already implicitly contained within the premises; it does not generate truly new information [43:50].
This "Law of Conservation of Information" (Dembski, 2005) is a fundamental phenomenon applying to all artificial learning methods [39:26].
Therefore, LLMs do not and cannot create endless new information; they primarily redistribute existing information [39:51].