Placeholder Image

Subtitles section Play video

  • Like maths equations, logic has a structure.

  • It looks a bit like: one, plus two, equals three. On one side of the equation we

  • have things we already know or agree upon.

  • On the other side is an answer that's true, so long as the numbers on the other side

  • don't change.

  • In logic, an idea is called a premise, which can be put together with other

  • premises in such a way that they lead us to a conclusion.

  • One premise might say magnets attract iron,

  • the other premise might be, this object is made from iron. Without seeing it

  • you can logically say that the magnet will attract this object.

  • But what if you swap around the information? Say, magnets attract iron and this object

  • is attracted to magnets.

  • Can you then say that this object is made from iron?

  • Unfortunately not. It still looks like logic but the conclusion no longer works.

  • Magnets not only attract iron, but other metals as well, such as nickel.

  • This broken logic is called a logical fallacy.

  • This particular example, is a formal fallacy. Because its form looks similar

  • to logic, but is false. In Latin and in legal circles, it's called a 'non sequitur' which

  • means 'does not follow.'

  • It's easy to mistake a logical fallacy for the real deal if you're not careful.

  • People do it all the time. Sometimes by accident and sometimes to fool you.

  • Knowing the structure of a logical argument is important. You wouldn't make the

  • mistake of thinking: three, plus two, equals one.

  • Rules are rules after all.

  • But breaking the rules of logic, can make an answer seem right,

  • when it isn't.

Like maths equations, logic has a structure.

Subtitles and vocabulary

Click the word to look it up Click the word to find further inforamtion about it