Arduino VCC connected to 10v supply with voltage divider connected to Ground?

My question is this. Can you connect a 10v regulated power supply to the arduino VCC pin, and then connect the arduino ground pin through a voltage divider between the positive and negative of the power supply? Essentially making a circuit that is +5v to -5v with arduino common ground at 0v.

Theoretically is seems this should work, but probably highly inefficient. Is this type of circuit possible, and what would be the best approach?

My goal for a circuit like this would be to use the logic level output of the arduino to engage a mosfet that requires a 10v voltage potential to fully saturate.

Dont.. Add a small signal transistor to pull gate low and a pullup R to drive gate high.

No.

The current pulled by the Arduino will seriously affect the voltage on the voltage divider, you can't pull any real amount of current from a voltage divider without having a ridiculous amount of current flowing through the 2 resistors (ie very low values and high power dissipation). It doesn't matter that you're using the ground pin, the current used by the arduino will skew the voltage. If you're using an old school Uno/Duemilanove/Etc with a built in voltage regulator, just feed the 10V into the power jack and let the Arduino sort it out. You could pull 10V out of the Vin pin.

Okay, thanks. Basically you're saying that for a simple circuit to drive the gate of a mosfet to 10v, I should just use additional hardware such as a transistor to drive the higher voltage to the gate of the mosfet and keep the circuit +10v to 0v.

But... Now my mind is wandering with this new challenge.

If such an occasion arose where one were to need a circuit that is +5v to -5v with arduino operating at +5v and ground at 0... How would this be achieved from a 10v power supply? This would be simple with two batteries regulated a 5v each, but how could it be done with a single regulated power supply?

You could do it as you said, with 2 resistors, but the current going thru the 2 resistors has to be 10x the current going into the arduino to have a chance at the voltage being somewhat steady as the arduino current draw changes.