People should be legally permitted to marry more than one person, in secular society.

It would appear that my opponents only real argument for the legalization of multiple marriage (in whatever form that may be since you have not specified) is that the government does not have any right to dictate the rules of marriage. I'm sure we would all agree to a lot of ideas involving the separation of state and marriage in many cases however I do not see how this is actually a good argument for the legalization of multiple marriage. You cannot say that something should be allowed solely on the fact that it isn't somebody else's business. i.e the government. That is not actually an argument, it is just a "why not" kind of case. It is basically like saying that person X is a racist and likes being racist therefore person Y has no right in telling them otherwise. It is the same concept and I think THAT is absurd. Now you can talk about group marriage not violating any human and individual rights however 1) I feel it can and does violate rights and morality. and 2) If everything that allegedly didn't deny human rights went smoothly then the world would be a better place but sadly that is not the case. An argument can't be made that something that doesn't deny rights should always be allowed, because there may be a million other disadvantages of allowing such a thing to occur. But even if that was a good argument I don't think it even applies here as I will demonstrate later on how anti-humanist group marriage is and can be. I'm not quite sure what you are trying to get across with your point about nature. You say "relations are natural and found in nature, and Homo Sapiens are also part of Nature, so denying polygamy is denying Nature. " Again I don't see how this is an actual argument for you stance. It is again more of a "why not". But this logic is flawed. Take if a man was to marry an underage girl for example. They are both Homo Sapiens and part of nature so therefore denying that marriage to be allowed would be too denying nature? So therefore that should be permitted too? It does not make sense. Here are some of my actual arguments against group marriage. As you have not specified what form of group marriage to discuss I will use Polygamy as an example. Here are some of my arguments against polygamy. 1. If a woman doesn't get along with her husband, they don't have to work it out, the man can just turn to his other wife (wives) and ignore her. She has no choice but to be submissive and helpless. This is the essence of the master and slave relationship. 2. Polygamy produces excess men. For every man who marries 4 women, three men can't find a wife. They will never have kids or buy a house or need to work hard and contribute to the economy. In countries where it is practiced, they tend to turn to gangs and rebellions. 3. Only the most wealthy man can afford it, but many others will take on too many wives and children and then expect the government to take care of them. This leads to major family crisis and money issues. For example, The FLDS polygamous Mormon sect took in millions in government money to keep going. 4. With polygamy wives have to compete for affection, time, food, and essentials for their own children. Men have little interest in being the referee. They often turn the money over to one wife and all others have to beg for items. They all want the best for their own kids at the expense of the other kids. Inequality among wives and children is inevitable. 5. Polygamy is mainly practiced in backwards countries (http://en.wikipedia.org.........). No one would want to move to one of these places. It only works when women's rights are eliminated so they have no choice. Again polygamy is a very unequal, and slave and master-like practice. Basically this form of group marriage is a miserable life for all but the dominant husband. Now here are some facts/statistics: A new study out of the University of British Columbia documents how societies have systematically evolved away from polygamy because of the social problems it causes. (http://www.publicaffairs.ubc.ca.........) Polygamous households contain jealousy and conflict among co-wives and Ethnographic surveys of 69 polygamous cultures reveals no case where co-wife relations could be described as harmonious. This leads to the tearing up of families.(http://www.jstor.org.........) (Remember I am just using Polygamy as an example, since you have not specified.) So I think it is fair to conclude that when discussing an issue such as this one, we have to look a bit beyond allowing it or disallowing it based on whether it has anything to do with the government or human "nature" as you say. I look forward to your response.