A fallacy I hear all the time is the fallacy of composition. A good example of this is where someone says “some of this political group are evil, so the whole group is evil”. They infer directly from some individuals of a group that the whole group must share that property. The whole group could be evil, but it is not shown through this argument.
Here is a simple example of the same reasoning that is obviously incorrect. I can form a square with two triangles. The fallacy of composition would be to say “one of those triangles has three sides, so the square as a whole must have three sides”. This obviously does not follow: the square has four sides.
So watch out for this fallacy in the wild.
#logic #philosophy #cambridgeuniversity #fallacy
