There have been a wide range of theories throughout history that attempt to explain the existence of Travelers. The following summarizes both past and current theories:

a. Religious Explanations

For most of history, the standard social explanation for Travelers was a religious one: they were individuals that were either speaking for God or speaking for the evil forces in opposition to God. There are several reasons for the continuing interaction of Travelers and religious tradition. Religions can provide a convenient explanation for an experience that may be frightening or mysterious. The Traveler can come from a religious community and have a background as a seer or a shaman, a priest or a nun. In addition, the Traveler experience can cause individuals to join an existing faith or religious community.

Travelers have been known to create their own sects or churches (i.e. the Divine Church of Isaac T. Jones in America). But, for the most part, established religions have rejected most Travelers and have joined the Brethren in resisting them. Established religions are hostile to divine revelations from outside their system. The best kind of prophet is one that died thousands of years ago and isn’t around to challenge existing theologies or hierarchies.

b. Psychological Abnormalities

The Eighteenth Century "Age of Enlightenment" in Europe, resulted in the wide scale confinement of the insane and a new way of thinking that saw the insane as being mentally abnormal – rather than touched by God. These ideas were used to explain the experiences of Travelers. Both philosophers and physicians suggested that Travelers didn't actually go anywhere, but were hallucinating.

The theories of Freud and his followers only reinforced this particular response. The Evergreen Foundation has consistently sponsored psychological studies that suggest that the Travelers are either harmless lunatics or dangerous psychopaths.

Freud had two sessions with a Traveler named Sarah Schultz in Vienna and the Tabula sponsored the publication of his pamphlet "The Case of Sarah S." (Freud believed that Sarah's visions of the four barriers were caused by her accidental observation of a gardener's genitals when he was urinating behind a tree).

In recent years, the Evergreen Foundation has encouraged the development of "psychotropic wellness" drugs to tranquillize an agitated population and sedate Travelers. (see also Zieglar Lab bombing )

c. Neurological Factors

In every normal person, the nervous system produces a mild electric charge. Travelers are able to increase this charge by an estimated 300%. As the charge becomes stronger, it shows a distinctive "pulsing" pattern. In the final phase, the Traveler's body seems to shut down and Neural Energy Monitors detect energy leaving the body.

d. Bio-Social Evolutionary Strategies

The Internet researcher Techtastic has suggested that there could be a larger bio-social explanation for the existence of Travelers. If the living world is one unified creation – that is, if all plants, animals and humans comprise a complex, symbiotic life form – then Travelers can be seen as an evolutionary response that increases that life form's survival.

Human beings react to harmful viruses by activating the blood's leukocytes and developing immunities. In the same way, Travelers create new ideas and new visions of cooperation in response to large-scale social "infections." In this theoretical model, the Travelers are the reason that the world has survived.