I wrote my senior thesis on this topic when I was completing my philosophy major. One of the best texts on the subject is &quot;Vagueness&quot; by Williamson.<p>It&#x27;s an arcane but super interesting topic that actually has  wide implications. It&#x27;s also IMO one of the most thorny problems in contemporary philosophy.<p>edit: I&#x27;m currently busy but can come back later to answer questions if anyone is interested.<p><a href="http:&#x2F;&#x2F;www.amazon.com&#x2F;Vagueness-Problems-Philosophy-Timothy-Williamson&#x2F;dp&#x2F;0415139805" rel="nofollow">http:&#x2F;&#x2F;www.amazon.com&#x2F;Vagueness-Problems-Philosophy-Timothy-...</a>