One sentence does not an article make. A single sentence cannot impart sufficient information on a reader on a subject in a significant, meaningful way without it becoming a dictionary definition—and there is a great difference between a dictionary and an encyclopedia.

As an example of a sentence, take "Harold Blowman (1957–1994) was an American actor best known for his performance as 'Billy' in the movie Don't Shoot the Monkey." This single sentence actually states more about the subject of the article than many stub articles of thrice the length which are "padded" with unsourced POV adjectives ("renown", "gifted", "highly-acclaimed", etc.) and dubious attempts at "notability through association" ("Blowman was part of the social circle that included [famous person A], [famous person B] and [celebrity C]").^[1]

But what does this sentence really say about Harold Blowman? Not much. It doesn't state who he was or establish whether he merits an article under Wikipedia's notability guidelines. Was his portrayal of 'Billy' commented on by film critics? Did he do other acting on stage or on the screen that garnered the attention of reviewers? Did his acting influence other actors? Was he associated with a particular notable director? Why did the editor spend a significant amount of their time to write this one sentence definition, and was that time well spent?

The last question can be answered definitively: NO. If an editor cannot find enough information on a subject to be able to write at least four non-repetitive sentences about the subject, then the article should not be started until there is sufficient information to "do it justice." If there is not enough information for at least four sentences of writing, it is most likely that the subject of the proposed article doesn't merit one in the first place under the notability guidelines.

One sentence "articles" clutter Wikipedia. Many of them create illusory blue links in lists; these give the illusion that otherwise-needed, fully developed essays and articles have already been written when in fact, there is nothing worthwhile there to educate the reader. These little pieces of flotsam and jetsam must be discarded for the betterment of the online encyclopedia: a redlink indicating no article is far superior to a deceptive blue link to nothing.

Therefore: All articles that are only one or two sentences long should be either expanded or deleted. Wikipedia decision-makers are urged to make one sentence "articles" a speedy deletion category as there is no purpose for them. While one sentence may make a good summary, it truly is not an encyclopedia article. Neither, for that matter, are two sentences.

That's right: Two sentences does not an encyclopedic article make, either, and should be treated accordingly.

This is an application of the reasonability rule: is it reasonable to expect that a single sentence is worth the time and effort to write and read with an expectation of being "illuminated" with encyclopedic information? Since it is not, one sentence articles (and, by a similar argument, two-sentence articles) violate the reasonability rule, as well as WP:NOTDICTIONARY, in the context of an encyclopedia.

• Wikipedia:Use common sense
• Wikipedia:Don't be inconsiderate
• Wikipedia:Put a little effort into it
• Observations on Wikipedia behavior