My initial thought is that this is probably fine and in fact should be protected, that is, assuming we're talking about another user.
Another user has the right to moderate (including deleting comments) on their posts, but they don't have the right to moderate what comments you put on your own posts. So I don't see on what grounds they could stop you posting the deleted comment on your own post any different from you posting any other comment.
On the other hand, if the comment was deleted by moderator for in some way having a strong negative effect [1] on the site (in moderator's judgment), then that effect may or may not be sustained if it's posted again elsewhere. It's hard to judge in advance of any particular case.
The tricky case will be when a user deleted a comment on the post when in fact a moderator would also have done so, but the user got to it first.
To conclude, feel free to do this. Use your judgment about why your comment was deleted before posting again. Mods will pay attention and intervene if we think the comment is actually bad to have on the site.
[1] The first thing that comes to mind is poor-epistemics/low-content/personal-attack-type comments.
This makes sense overall, but I am somewhat confused by the criteria you specify. Are either “poor epistemics” or “low content” really sufficient grounds for judging a post or comment entirely unsuitable for the site, even if posted on a user’s personal page? Forgive me for saying so, but this seems to indict quite a bit of what I see posted on people’s personal pages!
A) However bad you think the current content you see on the site is, I assure you the content from new users we delete is worse. (for comparison, recall that the entire rest of the internet exists, and the state that it's in. Many new users just haven't internalized the site culture at all)
B) I think it's plausible we should raise standards higher than we currently have, but doing a good job of it requires a lot more attention and manpower than we currently have.
Oh, ok, I see. I definitely had something different in mind when I read “poor epistemics” and “low content” in Ruby’s comment, but if you guys are talking about the sort of stuff that random drive-by trolls and such post, yeah, that makes a lot more sense. Thanks for clarifying!
I think downvoting things to minus infinity is almost always better than deleting them. (One exception is purging all content posted by new users banned for spam/nonsense.) A warning before temporary suspension of posting privileges if it's not heeded should be equally effective where a comment would normally be deleted as discouragement from further engagement in some current drama.
I do not necessarily disagree with you, but I’d like to request that discussions of whether it’s acceptable to delete comments, or to allow post authors to delete comments, etc., to be kept out of this discussion. My purpose here is just to establish whether this specific thing I am asking about is acceptable or not—I am taking site policy for granted right now.
This is a question for the Less Wrong moderation team.
Suppose that I post a comment on a post, and the author of that post deletes that comment. Now, that comment isn’t lost, per se (as its contents are sent to me via private message), but it’s no longer publicly accessible. This is likely to be unfortunate, from my perspective, as I sometimes write comments with the intention of having something I can then link to (and often the comment-thread context is relevant to the comment’s meaning).
Would it be permissible to make a post (of the “personal” type) where I re-post any of my comments that are deleted in this fashion? (I am assuming here that the reason for the comment’s deletion wasn’t anything like “having this comment on the site is illegal”, “this comment reveals privileged information”, etc. Likewise, I am assuming that any such comment does not violate any general site rules—despite that it may violate the commenting/moderation guidelines specified by a given post author—and so its presence on the site is not inherently problematic.)