1. Parkinson’s Law: Work expands so as to fill the time available for its completion.
2. Hofstadter’s Law: It always takes longer than you expect, even when you take into account Hofstadter’s Law.
3. Gates’ Law: Most people overestimate what they can do in one year and underestimate what they can do in ten years.
4. Goodhart’s Law: When a measure becomes a target, it ceases to be a good measure.
5. Hanlon’s Razor: Never attribute to malice that which is adequately explained by stupidity (or, don’t invoke conspiracy when ignorance and incompetence will suffice, as conspiracy implies intelligence).
6. Acton’s Dictum: Power tends to corrupt, and absolute power corrupts absolutely.
7. Amara’s Law: We tend to overestimate the effect of a technology in the short run and underestimate the effect in the long run.
8. Benford’s Law: In a diverse collection of unrelated statistics, a given statistic has roughly a 30% chance of starting with the digit 1.
9. Betteridge’s Law: Any headline which ends in a question mark can be answered by the word ‘no’.
10. Brooks’ Law: Adding manpower to a late software project makes it later.
11. Chesterton’s Fence: Reforms should not be made until the reasoning behind the existing state of affairs is understood.
12. Claasen’s Law: Usefulness = log(technology).
13. Clarke’s First Law: When a distinguished elderly scientist states that something is possible, they are almost certainly right, but when they state something is impossible, they are probably wrong.
14. Cromwell’s Rule: Nothing but logical impossibilities have a prior probability of 0 or 1.
15. Cunningham’s Law: The best way to get the right answer on the Internet is not to ask a question, it’s to post the wrong answer.
16. Doctorow’s Law: When someone puts a lock on a thing you own, against your wishes, and doesn’t give you the key, they’re not doing it for your benefit.
17. Dunbar’s Number: Most people can’t maintain stable social relationships with more than 150 people.
18. Eroom’s Law: Drug discovery is becoming slower and more expensive over time, despite improvements in technology.
19. Gell-Mann Amnesia Effect: You’ll believe articles outside your area of expertise, even after acknowledging that neighboring articles in your area of expertise are completely wrong.
20. Gibson’s Law (or the Expert Witness Law): For each PhD (to use as an expert witness for one side) there’s an equal and opposite PhD.
21. Godwin’s Law: As an online discussion grows longer, the probability of a comparison involving Nazis or Hitler approaches one.
22. Morley-Souter’s Law (Rule 34): There is porn of it (no exceptions).
23. Greenspun’s Tenth Rule: Any sufficiently complicated C program contains an ad hoc, informally specified, bug-ridden, slow implementation of half of Common Lisp.
24. Hebb’s Law: Neurons that fire together wire together.
25. Hubble’s Law: Galaxies recede from an observer at a rate proportional to their distance to that observer.
26. Hume’s Guillotine (Is-Ought Problem): Normative statements (about what’s moral/immoral/right/wrong) cannot be deduced exclusively from descriptive statements.
27. Humphrey’s Law: Conscious attention to a task normally performed automatically can impair its performance.
28. Kranzberg’s Law: Technology is neither good nor bad; nor is it neutral.
29. Lamarck’s Principle (or “Use it or Lose it”): Use it or lose it (evolutionarily speaking, but also in the brain).
30. Lewis’s Law: The comments you’ll inevitably find on any article about feminism justify feminism.
31. Littlewood’s Law: Individuals can expect miracles to happen to them, at the rate of about one per month.
32. Maes–Garreau Law: Favorable predictions about future technology will fall at the latest possible date they can come true and still remain in the lifetime of the predictor.
33. Metcalfe’s Law: The value of a system grows as approximately the square of the number of users of the system.
34. Miller’s Law: To understand what another person is saying, you must assume that it is true and try to imagine what it could be true of.
35. Moore’s Law: Computation per dollar grows exponentially (or: number of transistors per circuit doubles roughly every 24 months).
36. Murphy’s Law: Anything that can go wrong will go wrong.
37. Alder’s Law: What cannot be settled by experiment is not worth debating.
38. O’Sullivan’s Law: All organizations that are not actually right-wing will over time become left-wing.
39. Pareto’s Principle (80/20 Rule): For many phenomena 80% of consequences stem from 20% of the causes.
40. Peter’s Principle: In a hierarchy, every employee tends to rise to his level of incompetence.
41. Poisson’s Law (or Law of Large Numbers): For independent random variables with a common distribution, the average tends to the mean as sample size increases.
42. Pournelle’s Iron Law of Bureaucracy: In bureaucracy, those devoted to the bureaucracy get control, those devoted to what it’s supposed to achieve lose influence.
43. Putt’s Law: Technology is dominated by two types of people: those who understand what they do not manage and those who manage what they do not understand.
44. Rosenthal Effect (Pygmalion Effect): High expectations lead to an increase in performance, low expectations to a decrease in performance.
45. Schneier’s Law: Any person can invent a security system so clever that she or he can’t think of how to break it.
46. Shermer’s Law: Any sufficiently advanced extraterrestrial intelligence is indistinguishable from God.
47. Zipf’s Law: The frequency of use of the nth-most-frequently-used word in any natural language is approximately inversely proportional to n (few words are used often, most are used rarely).
48. Wirth’s Law: Software gets slower more quickly than hardware gets faster.
49. Sturgeon’s Law: Ninety percent of everything is crud.
50. Stigler’s Law: No discovery is named after its original discoverer, including this one.

This piece was first written on July 6, 2020, and first appeared on my website on May 30, 2026.