The Instigator
Pro (for)
10 Points
The Contender
Con (against)
0 Points

Incestuous marriages should be legal

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Post Voting Period
The voting period for this debate has ended.
after 2 votes the winner is...
Voting Style: Open Point System: 7 Point
Started: 12/13/2016 Category: Society
Updated: 2 years ago Status: Post Voting Period
Viewed: 589 times Debate No: 98002
Debate Rounds (4)
Comments (0)
Votes (2)




Debate Structure:
Round 1: acceptance
Round 2: Main argument
Round 3: Rebuttals
Round 4: Conclusion/reasons why you won
Debate Round No. 1


The first point I wish to make, is that there is nothing wrong with love between two consenting adults. I believe everyone believes that, and I personally also would say there is nothing wrong with doing anything that doesn't do harm to someone else.

I consider the burden of proof to be on con to show why incestuous marriages should be illegal. I don't see any legitimate reason why incestuous marriages should be illegal. The only objection most people have is a repulsive impulse that it's gross, but that is literally just opinion and there's no objective way to measure that something is "gross". It literally all depends on opinion, and if it is dependent on opinion, then there's no reason to make it illegal.

Now, there is the argument that babies from an incestuous couple have an increased chance of having defects. However, this is a completely different matter. I'm arguing that incestuous marriages should be legal, I am not arguing that incestuous reproduction should be legal. I do personally think it should be as well, and if my opponent is going to bring this up, I wish to point out that for first cousin sex, there is only a 1.7% to 2.8% increase in chances of birth defects [1] and for first degree incest(sex between parent and child or between siblings) there is in reality only a 6.8% to 11.2% increase for birth defects.[1] I don't consider these increases in chances for birth defects severe enough to make it illegal. Now, some studies(4 of them) conclude that it's higher, at 31.4% chance increase, however there are problems with these studies that were not taken into account, for example only 213 children were used, which is not quite a large enough sample pool, then each of them had a "lack of paternity documentation, young maternal age, possible parental diseases and/or intellectual impairment, parental socioeconomic status or lack of reporting this variable, and complications of unsuccessful attempted pregnancy termination" [1] which all would skew the data to increase the percentage higher than it is in reality. The 6.8% to 11.2% chances of birth defects comes from amplifying the third degree(first cousin) incest appropriately for how much more related siblings and parents/children are. This would be more reliable, as it makes sense. I know of no study which has taken into account all variables that could affect the birth defect chance, and limited it to that the only difference is that the parents of the children are related in the first degree.

Thus, it's not too harmful for first degree incest to occur, and there's not really any good reason why marriages between first cousins as well as siblings and a parent and offspring should be illegal. It should be also noted that in 18 states, first cousin marriage is completely legal in all instances[2] and I know of no huge problems being caused from the first cousins that are getting married in those states.



In the U.S. every state has some form of prohibition against incest,and for many good reasons.Incest is immoral and the Bible condemns it.High rates of birth defects and even death affects the children of people that practice incest.

Many of the laws in the United States originated from the Bible.We should take the advice of the Bible in this subject too.In Leviticus chapter 18,The Bible condemns all first-degree incestuous relationships.

As my opponent has stated,children of incestuous parents have 2 times the chance of having birth defects,Why risk endangering these children's lives.If incestuous marriage he made legal,they would be able to have kids. One of the main reasons for marriage is to have children,So you can't ban married couples from having kids.
Debate Round No. 2


I question why my opponent uses the Bible as reason against incest. I wouldn't consider it a reliable source, especially since there is at least one example of first-degree incest in the Bible that occurred that God didn't condemn in any way.

Lot's daughters got him drunk and had sex with him, and God did nothing to condemn this act.
Here is the passage from the Bible:

"Lot and his two daughters left Zoar and settled in the mountains, for he was afraid to stay in Zoar. He and his two daughters lived in a cave. One day the older daughter said to the younger, 'Our father is old, and there is no man around here to give us children"as is the custom all over the earth. Let"s get our father to drink wine and then sleep with him and preserve our family line through our father.' That night they got their father to drink wine, and the older daughter went in and slept with him. He was not aware of it when she lay down or when she got up. The next day the older daughter said to the younger, 'Last night I slept with my father. Let"s get him to drink wine again tonight, and you go in and sleep with him so we can preserve our family line through our father.' So they got their father to drink wine that night also, and the younger daughter went in and slept with him. Again he was not aware of it when she lay down or when she got up.So both of Lot"s daughters became pregnant by their father. The older daughter had a son, and she named him Moab; he is the father of the Moabites of today. The younger daughter also had a son, and she named him Ben-Ammi; he is the father of the Ammonites of today. [1]"

Not to mention, there is likely at least one other form of implicit incest at the beginning of the Bible. Adam and Eve are traditionally to be thought of as the first humans. Their kids had to have had sex either with each other or Adam or Eve in order to reproduce. This would have also been first-degree incest that God didn't condemn in the Bible.

Then there are plenty more examples of incest in the Bible, most of which never condemned by God [2]

So it would seem that God is inconsistent in his law about incest, since he seems to be okay with it in these instances, but later made a law against it in Leviticus. Thus, the bible is an unreliable source because it gives two different messages about incest.

Also, I didn't say they have 2 times the chance of having birth defects. I said that the chances of children of incest to have birth defects is increased by between 6.8% to 11.2%, which is much lower than twice the rate of birth defects among non-incestuous reproduction(for it to be twice as much, it would need an increased chance of 100%). I don't see this as being a big enough concern to make it illegal since that means a vast majority of offspring of incest do not have birth defects or die.

[1] Genesis 19:30-38


The Bible says that he shouldn't practice incest.As stated in Levictus, incest is wrong.
The reason incest was allowed at first is because the early humans had good genetics.The first human,Adam had perfect genes since God created him.Adam then sinned,sin was passed down through his descendants causing the worsening genes that we have today. Science has proven that incest causes birth defects,and since incest threatens the lives of babies, it should be banned.
Debate Round No. 3


I'd like to remind my opponent that this round should be used for conclusions and stating why you believe you won. No new arguments should be presented here. You can restate the arguments you've made previously though,

In conclusion, as I showed before, the increased amount of birth defects from incest is very small. The studies that show it is increased by over 40% had too many variables in them that also affected the rate of birth defects. In reality, the percent increase in birth defects from first-degree incest is between 6.8% and 11.2%. [1]I don't see why we should make it illegal for people who partake in incest to have babies when the chances aren't all that higher for birth defects.

In addition, I'd like to again point out that I was originally arguing for incestuous marriages, and incest in itself is a different matter. My opponent hasn't presented a real reason why two people related shouldn't be allowed to marry, they've only argued why they shouldn't have sex, which is an entirely different matter.

Therefore I believe that I have won since my opponent hasn't presented anything about why incestuous marriages should be illegal, and only has argued why incest itself is wrong. Even though this wasn't part of the original argument, I did show that first-degree incest doesn't have a high chance of birth defects. My opponent has only presented the bible as reason why incest is wrong, but the bible is not a scientific source, and has often been proven wrong. The bible is only a legitimate argument if we live in a society that considers the Bible to be the law, but most people don't live in such a society.




Why should something that is considered unnatural, condemned by the Bible, and proved to increase the risk of birth defects be legal. Incest may not cause birth defects most of the time,but it definitely increases the chance.Why take the risk of incest in marriage.
Debate Round No. 4
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2 votes have been placed for this debate. Showing 1 through 2 records.
Vote Placed by Cat47 2 years ago
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Total points awarded:30 
Reasons for voting decision: The only arguments Con used were continuously mentioning verses of the bible. Meanwhile, Pro made actual arguments.
Vote Placed by Agonist 2 years ago
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Total points awarded:70 
Reasons for voting decision: The Instigator made clear, well-reasoned arguments. The Contender Bible-thumped their way through each round. I find a single source to be unconvincing, especially when the source in question is being applied millenia after its authoring. I commend the Instigator at sticking to a good rhetorical presentation in the face of the Contender's farce.