While this isn't entirely true—he was mentioned in the posts Mea Culpa, Dinnertime conversations in an eccentric household, and Urban legends and bad poetry—they're all from last year.
The simple answer is that I didn't think he'd want me to mention him, especially in my recent posts about children's books. Yes, he sometimes listens to children's books in the car with me and his eight-year-old sister (usually as a captive audience), but I didn't think he'd want me to broadcast it. And, because he is gearing up to go to college next year, I guess I was granting him more independence, in my mind, than he would have as fodder for one of my blog posts.
The more complex answer is that I view his comics and short stories and doodles as his own creative/intellectual property, not something I can distribute without permission or that I should even ask permission to distribute.* They are his to do with as he wishes.
This begs the question, though—why do I feel that I can upload Emily's drawing and ideas but not his?
I suppose the main reason is that she doesn't have access to the Internet or other forms of distribution that he does, should he choose to share his stuff. I made that decision for her, then, when I shared samples of her Smiley Book Club and I'm not sure I entirely have that right. But I know, from past experience, that the titles from the Smiley Book Club are likely to disappear or rip or disintegrate in the next few years and be forgotten, and it was a way to preserve a sample of them electronically. And it was so perfect, to see the Smiley Book Club suddenly appear out of her backpack right after I wrote about listening to Andrew Clements' books. I hadn't known that his books (particularly Lunch Money) had had that much effect on her.
If blogs had been around when Isaac was young, I imagine I would have at least occasionally posted samples of some of his political cartoons and comics, particularly if they had been inspired by something he/we were reading. But the time has passed when I can post his childhood drawings—I don't want to embarrass him retroactively. And eventually, I suppose, Emily will want me to keep her drawings and books off my blog. I wouldn't want her to fear that showing them to me would risk their appearance on the world wide web.
So I have mentioned my son in my blog now. Perhaps this will be the last time he'll want me to mention him again, at least for awhile. But I'll certainly link to anything he chooses to put on the Internet in the future, proud mom that I am.
(* Addendum: Shortly after I initially posted this, Isaac suggested I add a picture of him as an illustration; he chose the digital self-portrait that now appears at the top of the post, which he drew this summer).