Someone asked [http://www.askphilosophers.org/question/1411], "How do we know our right hand from our left hand when there is literally nothing that can be said about one which cannot be said about the other"? Mark Lange posed this question in turn, "Suppose there were a universe that was utterly empty throughout its history except for a hand (unattached to any body) floating in it. (Pretty gruesome, but let's not think too hard about that!) Would that hand be a right hand or a left hand? Now we cannot appeal to the hand's relations to other things to give it its handedness, since there are no other things."
The thumb is on different sides of each hand. Put the palm down and you can tell which hand it is by looking to see if the thumb is on the inside or outside. What am I missing? Gloves come in left and right, you know? You could even tell this in a void.