Thou Shalt Not Commit Adultery ... Except?

Is It Still Adultery if Your Spouse Has Alzheimer's? - WSJ.com If you are a pastor, how are you going to counsel your people?  How would you preach about this? Some would say, "Yes, it is."  You took a vow of fidelity 'in sickness and health' and you should keep it. I have to admit that I have admired those spouses who have faithfully cared for their aging spouse with dementia or other illness. Their sacrifice appears heroic to me. Others would say, "No. That's really not my spouse any more." or "He or she would not want me to be lonely and committed to her body without her mind." Some are saying that I am keeping my vow of "in sickness and health."  I am not abandoning my care of or provision for this person.  I'm not even getting divorced. But relationally, the person who was my spouse for so long is no longer mentally there. I've grieved as if they had already died and have moved on. So the question people are really asking is, "What is adultery and faithfulness?"  Is it fidelity to a partner no matter their mental capacity, or is it fidelity only as long as they maintain their ability their ability to communicate? Certainly a problematic issue is what if a cure for Alzheimer's is found tomorrow and your spouse awakes to find you have moved on, perhaps with someone they don't approve of. I'm not sure you could point to any one Scripture text that addresses this issue definitively, so you have to look at the preponderance of the evidence.  I've been thinking about what Scripture texts deal with someone, anyone who doesn't have their mental faculties.  My wife thought of "whatever you do to the least of these" (Matt 25.40).  I thought of the compassion that Jesus shows the demon possessed but those are people who could be restored to sanity.  I also thought of God's faithfulness to an unfaithful people and the story of Hosea. I wonder if the Vatican has addressed this. They tend to think through these sanctity of life kind of issues. Perhaps the scripture text that does address it is, "Love your neighbor as yourself."  What would you want your spouse to do? Perhaps we should communicate that to them. What if there are children involved? How would they feel about it?