Semen causes cancer. lust is emotional gangrene, and other "facts" you can only learn from the Duggar family's homeschool curriculum.

All of the following courtesy of Gawker.

Did you know that non-spousal sperm causes cancer? Well according to materials from the Advanced Training Institute's homeschool curriculum, which the Duggar family used to learn all about sex and its many dangers, it does it totally does: 

Doctors have discovered that the seed of the man is an alien substance to the woman. It triggered responses similar to those of an “allergic” reaction. A woman who has a husband is able to develop “immunity” to this reaction; however, a promiscuous woman’s immune system becomes confused and unable to distinguish alien substances. This confusion is a key to the development of cancer.

I am going to go out on a limb and suggest that this refers to HPV which can in fact cause cervical cancer. However this is not due to the fact that a man's seed is "alien" to woman but rather due to the fact that the man picked up a dose from one of the other woman who he was sharing that seed with.

Of course all of this potential cancer is caused by lust. And lust is bad, bad, bad, bad, bad. (It really helps if you read that in the voice of Gomer Pyle.)

Armor of God, does that work better than a condom?

And medical diseases and diseases of the soul are linked.

Diseases of the body usually have their counterpart in diseases of the soul. There is, in fact, an intimate relationship between the health of the soul and the health of the body. 

By understanding the workings of a disease in one realm we can often gain significant insight to a corresponding disease in the other realm.

Ah, the old "bad things happen to sinners" argument. 

This was a popular idea in like the 16th century. Hard to believe that it is being taught to children in the 21st.

And remember men are not to blame for becoming all rapey, cause you know the gangrene of lust and all:

When a man looks lustfully at a woman, a flood of impulses travels through the optic nerve to the back of the brain. As a result, the glands and other bodily functions are activated, and the level of testosterone increases. 

Recent studies revealed a significant correlation between high testosterone levels and those who commit violent crimes.

You know that is exactly the same rational used in Muslim countries to convince women that an exposed elbow or ankle will drive a perfectly reasonable man crazy and fill him with the urge to rape the crap out of her.

It's never the man's fault after all.

There is of course much more over at Gawker but I think we now get a pretty good idea of exactly how the Duggar family received their education concerning sex.

Of course in no way does this excuse Josh Duggar's behaviors but it does help to explain the irrational environment in which he was raised.