Today's post, Changing Emotions was originally published on 05 January 2009. A summary (taken from the LW wiki):

Creating new emotions seems like a desirable aspect of many parts of Fun Theory, but this is not to be trivially postulated. It's the sort of thing best done with superintelligent help, and slowly and conservatively even then. We can illustrate these difficulties by trying to translate the short English phrase "change sex" into a cognitive transformation of extraordinary complexity and many hidden subproblems.

Discuss the post here (rather than in the comments to the original post).

This post is part of the Rerunning the Sequences series, where we'll be going through Eliezer Yudkowsky's old posts in order so that people who are interested can (re-)read and discuss them. The previous post was Growing Up is Hard, and you can use the sequence_reruns tag or rss feed to follow the rest of the series.

Sequence reruns are a community-driven effort. You can participate by re-reading the sequence post, discussing it here, posting the next day's sequence reruns post, or summarizing forthcoming articles on the wiki. Go here for more details, or to have meta discussions about the Rerunning the Sequences series.