It is challenging enough for the casual observer to tell the difference between the Fade and the creatures that live within it, let alone between one type of spirit and another. In truth, there is little that distinguishes them, even for the most astute mages. Since spirits are not physical entities and are therefore not restricted to recognizable forms (or even having a form at all), one can never tell for certain what is alive and what is merely part of the scenery. (It is therefore advisable for the inexperienced researcher to greet all objects he encounters.)