Only characters with a spirit can learn this skill. This Skill enables you to discern the presence of Spirits in an object, creature or area. It also enhances a number of skills, including the Diagnose Wounds skill when used on spirited creatures. It does not allow you to discern the magical traps known as Runes without also knowing the Discern Runes skill.
At the first level of Skill, your character can discern a spirit in an object or creature from a distance of two inches in front of their spell casting hand. The second skill level can increase the range at which spirits can be discerned to twenty feet directly in front of the characters spell casting hand. Other Discern skills can be increased to twenty feet with this level of skill. At the third level of this skill, the range is increased to twenty foot radius, centred on the character, the character can sense the number of creatures with a spirit and spiritual objects in the area, but must point his or her spell casting hand directly at one to determine its location. Other discern skills are increased to match the range.
At the fourth level of proficiency in this skill, the location of all spirits, whether in an object or part of a creature can be determined if within twenty foot of the character, Also, the character can detect any spirits within forty feet directly in front of their spell casting hand, again this increases the range of other discern skills. At fifth level of proficiency the character can determine the alignment of any spirit within range, they can also tell the direction to the Spiritual North Pole of the world, and the type of spiritual spell or effect present by revealing the spell list that the effect was cast from, but not necessarily the exact spell. Finally, at fifth level of proficiency, the range of this skill and any other discern skills are increased to twenty feet centred on the character and a circle twenty foot in radius, up to forty feet away. In general you can discern spirits though normal objects such as walls, doors, chests, etc But there are methods to make mundane objects impenetrable to this skill but they are very expensive, and normally only available to Guilds or other people with similar power and wealth.
Please see the attached image to see a diagram of the different levels.