Law professor William Jacobson discusses the slippery-slope argument against homosexual "marriage." The argument is that, if two men or two women are allowed to marry, there will be no principled reason to prevent three or more individuals from marrying. Since (presumably) we do not want to allow this, then we should not take the first step onto the slope.
Along the way, Professor Jacobson calls "stupid" the argument that allowing homosexual "marriage" will lead to humans marrying dogs. I don't think this argument is stupid. Some of the arguments that support homosexual "marriage" also support allowing humans to marry animals. For example, animals, no less than humans, can be beneficiaries under intestacy and probate laws. Animals, no less than humans, have health needs. A human could claim to love a dog or other animal just as much as any human loves a human. And so forth.
You may not be persuaded by this slippery-slope argument, but that doesn't make it stupid. Many people aren't persuaded by Professor Jacobson's slippery-slope argument, but I don't think he would consider it, on that account, stupid.
Keith Burgess-Jackson, J.D., Ph.D. 