Canada is debating the decriminalization of the personal possession of small amounts of marijuana. I heard a representative of a police association on the CBC the other day make an argument that I recognized from my Practical Logic philosophy course.
Unfortunately, I don’t have a link to the original quote, but the argument was roughly this: 100% of heroin addicts in Canada started with marijuana. The implied premise here is this: therefore, smoking pot leads to heroin use.
This is called affirming the consequent. If A then B. B therefore, A. It’s wrong. All leprechauns drink Guinness. You drink Guinness, therefore you are a leprechaun.
I know this isn’t a new argument, in fact, it’s quite obvious. That’s exactly why I thought it was notable. It was so obviously a logical fallacy that I was amazed that it was stated so simply.
Perhaps we should be teaching the basics of arguments and fallacies in grade school.