Elliotte Rusty Harold, author of XML in a Nutshell and keeper of the Cafe Con Leche XML news site, defends XML against “an extreme Aristotelian tendency in the XML world that tries to lock everything down and insist that there’s only one way to do it, that all documents must adhere to a schema, that there can be
only one schema per document, and even that there can be only one schema language.”
These comments came during a discussion on the W3C Technical Architecture Group about a “Skunkworks” XML 2.0 spec Tim Bray had written. Some people wanted to see processing instructions removed completely, noting their wide-open content and freedom from schema constraint.
Harold’s conclusion is a reminder that XML’s flexibility is what gives it so much power:
“XML is not Aristotelian. It’s fuzzy, and that’s part of its power and its usefulness.“
Would you like some Platonic Forms with your schema? Or do you agree with Thales that “everything is water”?