Logical Fallacies

Ad Hominem Attacking the person making an argument rather than the argument itself.

Appeal to Authority Claiming something is true because an authority figure says so, without evaluating the argument's actual merits.

Appeal to Emotion Using emotional manipulation instead of logical reasoning to persuade.

Appeal to Nature Claiming something is good because it's "natural" or bad because it's "unnatural."

Bandwagon Fallacy Claiming something is true or good because many people believe it.

Begging the Question Assuming the thing you're trying to prove as part of your proof (circular reasoning).

Cherry-Picking Selecting only evidence that supports your position while ignoring contradicting evidence.

False Dilemma Presenting only two options when more exist.

Hasty Generalization Drawing broad conclusions from insufficient evidence.

Post Hoc Ergo Propter Hoc Assuming that because B followed A, A caused B.

Red Herring Introducing an irrelevant topic to divert attention from the actual argument.

Slippery Slope Claiming one thing will inevitably lead to extreme consequences without showing the causal chain.

Straw Man Misrepresenting someone's position to make it easier to attack.

Tu Quoque Dismissing an argument because the person making it doesn't practice what they preach.

Cognitive Biases

Anchoring Over-relying on the first piece of information you encounter.

Availability Heuristic Judging likelihood based on how easily examples come to mind.

Backfire Effect When correcting misinformation strengthens the original belief.

Confirmation Bias Seeking, interpreting, and remembering information that confirms what you already believe.

Dunning-Kruger Effect The less you know about something, the less you realize how much you don't know.

Fundamental Attribution Error Attributing others' behavior to character while attributing your own to circumstances.

Halo Effect Letting one positive trait influence perception of other unrelated traits.

Hindsight Bias Believing, after learning an outcome, that you would have predicted it.

In-Group Bias Favoring members of your own group and being skeptical of outsiders.

Loss Aversion Feeling losses more strongly than equivalent gains.

Motivated Reasoning Reasoning backward from desired conclusions to supporting arguments.

Negativity Bias Giving more weight to negative information than positive.

Optimism Bias Believing you're less likely to experience negative events than others.

Recency Bias Giving more weight to recent events than older ones.

Selection Bias Drawing conclusions from a non-representative sample.

Status Quo Bias Preferring the current state of affairs simply because it's current.

Sunk Cost Fallacy Continuing an action because of past investment rather than future returns.

Survivorship Bias Focusing on successes while ignoring failures that are less visible.

Critical Thinking Concepts

Base Rate The underlying frequency of an event in a population, before considering specific circumstances.

Bayesian Reasoning Updating beliefs proportionally based on new evidence.

Calibration The accuracy of your confidence levels — being right 70% of the time when you're 70% confident.

Crux A point where, if you changed your mind, you'd change your overall position.

Epistemic Humility Acknowledging the limits of your knowledge and being open to being wrong.

Epistemic Hygiene Practices that maintain the accuracy and reliability of your beliefs.

Expected Value The probability-weighted average of possible outcomes.

Falsifiability The property of a claim that makes it possible to prove wrong. Unfalsifiable claims aren't testable.

Intellectual Honesty Commitment to truth over winning arguments or maintaining beliefs.

Motivated Skepticism Being more skeptical of claims you don't want to believe.

Null Hypothesis The default assumption that there is no effect or relationship until proven otherwise.

Outside View Using base rates from similar situations rather than relying on specific circumstances.

Pre-Mortem Imagining a decision failed and working backward to identify what went wrong.

Reference Class A group of similar situations used for comparison when making predictions.

Second-Order Thinking Considering the consequences of consequences, not just immediate effects.

Signal vs. Noise Distinguishing meaningful information from random variation.

Steelmanning Building the strongest possible version of an argument you disagree with.

Straw Man A weak or distorted version of an argument that's easy to defeat.

Evidence and Sources

Anecdotal Evidence Personal stories and individual examples, as opposed to systematic data.

Burden of Proof The obligation to provide evidence for a claim, typically on whoever makes the claim.

Correlation A relationship between two variables, which may or may not indicate causation.

Causation When one thing actually causes another, not just correlates with it.

Confounding Variable A third factor that influences both variables being studied, creating a spurious correlation.

Control Group A group in an experiment that doesn't receive the treatment, used for comparison.

Meta-Analysis A study that combines results from multiple studies on the same topic.

Observational Study Research that observes existing data without experimental manipulation.

P-Hacking Manipulating data analysis to find statistically significant results.

Peer Review The process of having research evaluated by other experts before publication.

Publication Bias The tendency to publish positive results more than negative or null results.

Randomized Controlled Trial (RCT) An experiment where participants are randomly assigned to treatment or control groups.

Replication Repeating a study to verify its results.

Selection Effect When the process of selecting subjects creates bias in the sample.

Statistical Significance The likelihood that a result is not due to random chance.

Systematic Review A comprehensive review of all research on a specific question.

Dialogue and Argumentation

Bad Faith Engaging in discussion with no intention of genuine exchange or potential mind-change.

Burden of Proof The responsibility to prove a claim falls on whoever makes it.

Charitable Interpretation Interpreting someone's argument in the most favorable reasonable way.

Devil's Advocate Arguing a position you don't hold to test the strength of opposing arguments.

Gish Gallop Overwhelming with many weak arguments rather than developing strong ones.

Ideological Turing Test The ability to argue for a position convincingly enough that holders of that position would think you're on their side.

Good Faith Engaging in discussion with genuine openness to learning and potential mind-change.

Moving the Goalposts Changing the criteria for what would satisfy an argument after the original criteria are met.

Principle of Charity Interpreting unclear arguments in the strongest reasonable way before critiquing.

Socratic Method Teaching or exploring through asking questions rather than making assertions.

Epistemology

A Priori Knowledge that can be known independent of experience.

A Posteriori Knowledge derived from experience.

Empirical Based on observation or experiment.

Epistemology The study of knowledge — how we know what we know.

Justified True Belief The classical definition of knowledge: a belief that is both true and held for good reasons.

Knowledge Belief that is both true and justified.

Objectivity Independence from personal biases or perspectives.

Rationalism The view that reason is the primary source of knowledge.

Skepticism Questioning the possibility of certain or complete knowledge.

Subjectivity Dependence on personal perspectives or biases.

Truth Correspondence between belief and reality.