Academic papers have abstracts because a very large percentage of their readership won't read the main article. (For one thing, the abstract has traditionally

Academic papers have abstracts because a very large percentage of their readership won't read the main article. (For one thing, the abstract has traditionally been free to read and is indexed by library tools like PubMed, while the whole paper has traditionally cost a small fortune and/or required a subscription and/or required a trip to the library stacks and a very tedious photocopying session. What scholars used to do before the photocopier I have no idea. Maybe they had that tidy handwriting because they got a lot of practice.) (Even in the modern era, abstracts can be useful because scientific papers have a required format that makes them bulky and hard to skim. But, a hint: It's often better to skim the first few paragraphs and the last few paragraphs of a scientific paper than to read the abstract. The first section contains the references to prior work, which help you put the paper in context and give you hints about where to look next; the ending has the more-detailed version of the conclusions, with fun bonus features like attempts to pre-empt the obvious criticisms, speculation about what the work might really mean, previews of coming attractions, and sometimes even hints about where the bodies are buried.) Meanwhile, bureaucratic memos have Executive Summaries because they serve at least two audiences. If you delete the executive summary nobody with any political power will read your memo -- executives read only one sentence at a time -- and your proposal will die alone. If you delete the body you will lose all of the ass-covering detailed analysis that you carefully larded it up with, and six months later someone will accuse you of not thinking your crazy idea through. But essays don't have abstracts. It's like telling a story by first spoiling the ending, or telling a joke by leading with the punchline. If the story promises to be so boring in the telling that it's not worth following along, don't tell the whole story.