Beliefs and ideas that most people accept as being true are known as conventional wisdom. According to conventional wisdom, it's much easier to train a dog than a cat.
Conventional wisdom has often been shown to be true over time. Evidence proves that, aside from unusual felines, it's much easier to teach a dog to sit than to convince a cat to do anything. But automatically accepting conventional wisdom can also mean failing to stop and think about it. Just because conventional wisdom says that walking on a tightrope between skyscrapers is impossible doesn't actually mean it can't be done!