Why are dogs and cats enemies?

Most people believe that dogs and cats share a stereotypical, mutually hateful relationship. However, the truth is far from it...
Nature:
While cats and dogs don't hate each other naturally, they do have different temperaments. While dogs are more playful and social creatures, cats like to be independent. This difference in behaviour is the reason you may not see the two animals getting along famously.
Habits:
Both animals also differ in the way they are trained. So, while dogs are trained to chase and hunt while playing, cats are more likely to take this as a threat. The resulting chase makes us feel like they are sworn enemies when it's just a harmful game of catch.
Introductions
The way the two animals are introduced matters a lot, because dogs see themselves as pack leaders, while cats are more about territory control. When they meet, their body language creates confusion. If the dog raises a paw as a friendly gesture, the cat, at times, takes it to be a threat. This may result in the animal hissing and trying to prevent what it sees as an attack on itself.