1. Screwtape describes middle-age life as "excellent campaigning weather" because he also says it's so hard for people in that stage of life to persevere. Do you think it's difficult in the same sort of way that the middle of the week can be difficult to get through because you're not just starting nor are you getting all that close to finishing?

2. I think it's because they tend to have more "invested" in the world. They generally have work, a spouse and children, friends and extended family, and some ambitions still. They still have responsibilities and they're getting set in their ways---hence they're not as likely to be as keen to leave.

3. I think Screwtape is saying that experience tends to allow people to maintain a facade of virtue and goodness without really being virtuous or good. As best I can tell, Kant says that experience tells us how things are done, but not how they should be done. So, I think they're pretty close to saying the same thing. Maybe?
In the case of virtue, I think experience can be harmful because it can tend to jade you. It's hard to hold to and follow ideals when you're out in the world---not very many people hold to virtue, so you'll stand out (not always in a 'good' way either) if you do.

1. Yes Middle-age!

ValiantArcher said it best!

Do you think it's difficult in the same sort of way that the middle of the week can be difficult to get through because you're not just starting nor are you getting all that close to finishing?

Yes, Could not have said it better!

2. What do you think of the claim that humans grow more attached to the world as they grow older?

I think the longer we live here on earth the easier we can grow attached to the world, People, Jobs, Plans we make. We can get really comfortable, it can be easy to forget this is our temporary home.
It would be easier to move out of an empty house, but it would be harder to leave a house full of everything. (quick analogy).

1. What part of life is Screwtape describe as "excellent campaigning weather"? Why?

Middle age (hey, I resemble that remark! ). Life has settled down to a comfortable, predictable routine - maybe it's even boring. All the better to offer temptations! And he adds that if there's prosperity, then all the better, for it allows the world to further ingratiate itself into a person.

2. What do you think of the claim that humans grow more attached to the world as they grow older?

I think this is often the case, for reasons already mentioned: the making of more and more friends (friendships lasting 30 or more years can be hard to give up), the comforting routine of job and family; the accumulation of wealth and possessions.

Yet I think there can be a tipping point when things might go the other way. I know I have fewer years left on this earth than I've already lived. Old age and the prospect of death shadow some I love. And for those even older, like my parents, understanding that death is near can make a big difference. Rather than trying to hold on to material things, the realization that such things are fleeting has prompted some older people I know to begin shedding their accumulated stuff so that their kids won't have to deal with it later. Not to mention the growing perception that there are things that really matter, such as friendships with others and spiritual matters.

(That is to say, once people get old enough, they may actually have less of the incapacitating connection to the world that Screwtape lauds here).

1. What part of life is Screwtape describe as "excellent campaigning weather"? Why?

The part of life that we are discussing is middle-aged prosperity or middle-aged adversity. It is hard for people to just continue on to those long years that they seem to be doing the same thing every day. If the human keeps failing at what they are doing they are greatly depressed and tend to give up eventually. If they are successful at what they are doing then they could be built up to the point of thinking of earth as home and only caring about the earth.

2. What do you think of the claim that humans grow more attached to the world as they grow older?
Yes, I think that does happen. Now, it definitely does not happen to everyone and I think most people are attached to the things or people they have in this world and not the world it self. But it is kind of like living in the same neighborhood all your life. If you are in a good neighbor and you have good friends there you will want to stay there. But if it is a horrible neighborhood and you have no friends you will not really want to stay there no matter how long you lived in that place. Although if you have good memories in that neighborhood you might want to stay there anyway.

1. What part of life is Screwtape describe as "excellent campaigning weather"? Why?
Middle age. If they have not been "successfully," this is the time they begin to feel tired of the recurring trails and temptation. They have outgrown or lost there youthful hopes and loves. If they have been "successful," they can easily be directed to what they have and forget about everything else. They feel at home on the earth.

2. What do you think of the claim that humans grow more attached to the world as they grow older?
In a lot of cases, I think it is true. The longer people live the more time they have to get more possessions and make more friends. On the other hand, I believe some people get tired of life and are ready to go when it is their time.

3. Screwtape writes: A great human philosopher nearly let our secret out when he said that where Virtue is concerned "Experience is the mother of illusion"; This is a paraphrase of the following quote.

Do you think Screwtape's paraphrase accurately represents what Kant is saying? If not, what do you think Kant is trying to say? People tend to think that experience is very important. Why is it harmful in the case of virtue?
Screwtape seems to have covered the main point. I think what they are saying is that experience cannot teach you to be virtuous. You can learn from experience that lying gets you into trouble, but that experience would not necessarily teach you that ethically it is wrong to lie. Basically, from experience you can learn what other people do and what is socially acceptable but not so much what you ought to do. I think there are cases that experience could help to someone figuring out ethical laws, but it isn't guaranteed. For example, if a person is made a slave, they could either learn that it is wrong to own other people or learn that it is better to own other people before they can own you.

2. What do you think of the claim that humans grow more attached to the world as they grow older?

Yet I think there can be a tipping point when things might go the other way.

I would agree. Middle age is different than old age. It seems people tend to get attached to the world in the middle, but I agree that things change in old age. One knows that there isn't much time left and prepares. When you are facing death, you get ready to go. Also when you have loved ones in Heaven the longing to meet them again grows stronger. But all in all it seems that people who are old may do a great amount of reflection and work to purge any worldliness that is trying to cling to them. They are removing the excess baggage, so to speak.

It would be easier to move out of an empty house, but it would be harder to leave a house full of everything.

A house might be empty because you are just moving in, or because you are preparing to move out.