An adage is similar to a "rule-of-thumb" or proverb. Some of these might help you to simplify decision making, whilst others might seem logically faulty or incorrect – it is up to you to decide.
Listed below are some of my favourite philosophical adages:
In life
- Betteridge's Law Any news or journalistic headline that ends in a question mark can be answered simply with the word "No". This one will save you a lot of time when browsing websites or newspapers.
- When you hang around the barbershop long enough, sooner or later, you will get a haircut If you spend time in a place where something typically happens, or around a group of people who partake in certain activities, don't be surprised if one day you find that thing happening to you. I thought about this a lot whilst reading "Nuclear War: A Scenario" by Annie Jacobsen, you can have all the will in the world to rely on "nuclear deterrent" as a reason never to actually arm and then fire a nuclear weapon, but eventually, someday, someone is going to do so.
- Half a loaf is better than none Something is (usually) better than nothing. As much as I support the central idea of Marie Kondo's masterwork "The Life-Changing Magic of Tidying" that less is more, this can occasionally collapse when pushed to an extreme. People need things to survive: food, water and shelter at a basic level. We also benefit greatly from tools and clothing. The things we don't need to survive such as art, music, games or toys, will often enrich our souls, but can also arrest our capability for growth.
- Hanlon's Razor Try to avoid attributing to evil or malice what could be explained by stupidity. There are many examples of evil and corruption in the world throughout history, but more often than not, foolishness or indifference is more common a motive than malice.
- Hitchen's Razor You can safely dismiss any argument that is presented without evidence, without any evidence. Named after Christopher Hitchens.
- Murphy's Law Anything that can possibly go wrong, will inevitably go wrong at some point. The movie "Interstellar" is a good example of this law pushed to an extreme to tell a science fiction story.
- Muphry's law When writing any form of criticism of editing or proofreading, you yourself will inevitably make a fault of some kind within your own criticism. This is a deliberate mispelling of "Murphy's Law".
- Occam's Razor The simplest explanation is usually correct.
- Sturgeon's Law 90% of just about everything is awful. I suspect this could be a real-world manifestation of pareto distribution.
- Cunningham's Law Named after Ward Cunningham (the inventor of 'Wiki' software), the adage states "the best way to get the right answer on the internet is not to ask a question; but to post the wrong answer" and then wait for the corrections to roll in!
In engineering
- Don't repeat yourself (DRY) Try to centralise calculations, tools or functions wherever possible to avoid repetition.
- You aren't gonna need it (YAGNI) I like to plan for the future: it appears optimal to avoid wasting time if you can foresee and fix a problem before it happens. YAGNI encourages creating what is needed and nothing more. Often in practice, when you create for the future rather than for right now, what you make is either not needed, or eventually needs to change as a result of additional clarity or changes in scope.