A thief in a dream often points to a fear of loss -- of security, trust, or something you've worked hard to build -- more than any actual theft. Being robbed in a dream can reflect a violation you've felt in waking life, even one that's emotional rather than material. Catching or confronting the thief may suggest you're ready to reclaim something you feel has been taken from you.
Positions are as fundamental as conjunctions for talismans. - Picatrix (Andalusia, ~1000.AD)