When the conditions are right, spirits who wish to interact certainly will. It is a natural process, just as it will rain when atmospheric conditions are fitting. The relationship of human beings and spirits has always existed, and always will.

The way in which a spirit becomes visible follows a universal pattern of manifestation comprising progressive stages. This pattern applies regardless of whether it is a human spirit or one of the other sublunary entities. All these stages of manifestation occur at one simultaneous moment, but our perception and the environmental conditions dictate what we see. It is apparent the spirit does not have control of this process, nor are they affected by it. They do not choose at which stage of manifestation they will appear, and their perception of their own reality is not shifting. Our traditions identify four stages of visible manifestation, as follows:

1. Nube
   Often the first visible stage of manifestation will be a cloud or mist representing the the stirring of phasma around the spirit. This cloud, or nube, can sometimes be seen with the naked eye, but a person with the second sight can see it readily. It is often captured on film by paranormal researchers. The color of the mist can indicate the type of spirit manifesting. For a human spirit, the cloud or mist will be silvery gray, like tobacco smoke.
   
   
2. Numen
   The stage of manifestation following (and sometimes during) the appearance of the cloud or mist is the emergence of a dense sphere of luminous aether known to magicians as the spirit's form of fire and to paranormal enthusiasts as a spirit orb. The numen is the indication of the ens or soul and verifies that a spirit is sentient. Paranormal investigators consistently capture photographic and video evidence of orbs with differing density, shape, and color. True orbs are self-illuminating and of a distinct composition. A numen can often be seen with the naked eye. When a numen is in motion, it can appear as a white rod or streak.
   
   
3. Umbra
   If the spirit manifests further, it presents as a dark but recognizable silhouette known in magic as the umbra, or shadow, and it is the most common specter that you will encounter. When it is a humanoid umbra, it becomes what paranormal researchers call a shadow person; however, this term has unfortunately accrued the additional moralistic interpretation as an evil nonhuman spirit. This error has caused an irrational fear that has infected the subject of "shadow people" on the internet and within the paranormal community in general.
   
   
4. Apparition
   Lastly, the form of the spirit presents as if it were composed of translucent light and, at times, transparent but of natural color. Infrequently, the apparition may appear as an opaque form indistinguishable from a living being.
   
   Apparitions are sometimes more easily seen as a reflection, whether in a mirror or glass, or captured by a camera with a mirrored lens. When a spirit is seen from upstairs window, it is sometimes assumed they are hovering outside above the ground, but it is more likely the spirit is standing near you and you are actually seeing their reflection in the glass.
   
   Another frequent sighting of apparitions occurs when people awaken from sleep to see a spirit on or around their bed. This is usually a sign they have tried to communicate with you while you are in a receptive dream or semiconscious state. Sometimes they may even appear to be floating horizontally above the bed, looking directly at you. People are often frightened by this, but it is simply the spirit trying to hold a conversation with you while you are lying down.

Excerpted from Unquiet Voices, by Rob and Nonie Douglas.