The mental world is an ontological category in metaphysics, populated by nonmaterial mental objects, without physical extension (though possibly with mental extension as in a visual field, or possibly not, as in an olfactory field) contrasted with the physical world of space and time populated with physical objects, or Plato's world of ideals populated, in part, with mathematical objects.

The mental world is an ontological category in metaphysics, populated by nonmaterial mental objects, without physical extension (though possibly with mental extension as in a visual field, or possibly not, as in an olfactory field) contrasted with the physical world of space and time populated with physical objects, or Plato's world of ideals populated, in part, with mathematical objects.