Are you debating in favor of it, or against it?
If you are against it, then the #1 argument is that it is unconstitutional. The Constitution sets down a very limited set of powers for the federal government, and explicitly states that anything not listed is to be left to the individual states (10th amendment). No place in the Constitution does it give Congress permission to implement welfare programs, therefore, it is illegal for the federal government to have a Social Security program, only the states can do it.
Regardless, even if it was not illegal, it would still be a bad idea because it is unethical, immoral, and a violation of basic human rights. The ONLY source of revenue the government has is taxes (the citizens' money). So, the ONLY way the government can give money to one citizen, is by taking it from another. So the ONLY way the government can provide a service like Social Security is by violating the basic human right of property ownership. This can not be justified, no matter how good your intentions.
