Eclipse 2002 4 cylinders won't start

It sounds to me that the starter doesn't engage to the flywheel. There is a mechanism that engages and disengages the starter to the flywheel and in rare cases can fail or stuck.

Still, you should be able to push start the car, if it doesn't start like this, then might be something more serious, but I'm sure you would know more about it.

However, I would first make sure that no fuse or relay is blown by following the wiring diagram in order to spot all the related circuits.

Before you replace any parts you could check if the starter engagement mechanism draws any current. If it does try tapping on the starter motor with a small mallet just to shake it a bit in the hope that it will unstuck it.

In case that the engagement mechanism doesn't draw any current, try to find on the electrical diagram the next place to check in case you missed anything or if any wire is lose.

Finally if all wiring is fine, then most likely you need to replace the starter.