What's the use of philosophy?

Take a look at this article in The Stone section of the NYT by Gary Gutting.

Even though basic beliefs on ethics, politics and religion do not require prior philosophical justification, they do need what we might call “intellectual maintenance,” which itself typically involves philosophical thinking.

I find the idea very interesting. Think of a car, or any industrial device and the need for maintenance. What is maintenance in this sense?

1. The act of maintaining or the state of being maintained.

2. The work of keeping something in proper condition; upkeep.

I take this metaphor of maintenance as thinking outside the box. And that¡s generally what the best thinking is about.