Abraham Lincoln was fond of repeating this riddle:
"If you call a dog's tail a leg, how many legs does it have?"
Of course there were morons who replied "five"; but of course there were mostly intelligent people who realized that just calling an appendage a leg did not make it a leg (although many men who were in the service are familiar with observing in the common shower facilities another male who was so endowed as to be said to have a "third leg"; but we regress...)
Come now the American Statist Progressives, who as usual wish to answer any question so as to be taken in a way which will benefit their broader argument. Ask an ASP this riddle and he will say something along these lines:
"Well, it depends. There have been great advances in veterinary medicine in the last few decades, so if the dog had been crippled it is entirely possible that his tail and the controlling muscles might be adapted for locomotion and thus considered a leg. And if part of the crippled leg still played a part in the dog's locomotion, you might say the dog had five legs. But if the affected leg were useless or missing, then the dog would still have only four legs. And if the tail did not compensate sufficiently for the missing leg, then the poor animal would have in reality only three legs."
Straight answers are an uncommon commodity among ASPS.