> According to the cybernetician, the purpose of a system is what it does. This is a basic dictum. It stands for bald fact, which makes a better starting point in seeking understanding than the familiar attributions of good intention, prejudices about expectations, moral judgment, or sheer ignorance of circumstances.

— Stafford Beer, 2001 (via Wikipedia: https://en.wikipedia.org/w/index.php?title=The_purpose_of_a_...)

I think that's a reasonable and insightful definition, but I don't think that's what most people are likely to think when they read the words I quoted.