Many thoughts on especially design recently lead me to the conclusion that defining the terms art, design, and decoration can be pretty simple. Outlining their principles, at least. Simpler than I thought in school (anyone remembering these “what is art” questions?), and also simpler than I thought in recent years.
Art hides. Art has a meaning, and it hides it, on purpose. Art delivers a message, and that message is hidden, on purpose. It is an art to create art. Art is unusable, by definition.
Design reveals. Design reveals meaning, design reveals a message, design reveals function. Bad design does the opposite: It obscures, it hides. The reason why that almost never makes bad design art is that the subject is supposed to be revealed.
Anything else that doesn’t have meaning is just decoration, at most. Ask an artist what he wants to achieve with his art piece—if he can’t (well, maybe he won’t) tell, he’s a decorator, not an artist. Ask a designer why her design works—if she can’t tell, she’s probably a (lucky) decorator, not a designer. Decoration’s sometimes appealing, but it doesn’t transports anything.
These definitions are simplified, sure, so they’re rather principles or attributes of art, design, and decoration. They rely on other definitions, for example “meaning”. They also ignore certain factors like audience, context, and emotion.