Hermetic Beliefs
Hermeticism covers entirely too broad a range of topics to discuss them all fully, but the general Hermetic worldview focuses on the nature of the cosmos and of mankind, especially the dual nature of reality (lower physical reality versus higher divine ideal reality), and of the rule of Fate over the lives of men and how it may be overcome. This is quite clearly demonstrated by selected excerpts from the Poemander, which is written as a divine revelation and presents the Hermetic paradigm through its story of the creation of the world, the "fall" of man, and the eventual re-ascent of man. The text opens with the beginning of a dream-like revelation, where a being who calls himself Poemander introduces himself to the narrator, who remains nameless. After asking for knowledge, the narrator is treated to the story of creation, where the primal form of nature is darkness which becomes a "moist nature":

Thereon out of the Light a Holy Word (Logos) descended on that nature. And upwards to the height from the Moist Nature leaped forth pure Fire; light was it, swift and active too.
The Air, too, being light, followed after the Fire; from out of the Earth-and-Water rising up to Fire so that it seemed to hang therefrom. But Earth-and-Water stayed so mingled with each other, that Earth from Water no one could discern. Yet were they moved to hear by reason of the Spirit-Word (Logos) pervading them (Mead, Poemandres, 5).

This is a description of the separation of lighter elements (air and fire) from heavier elements (earth and water), the beginning of the Hermetic dualism - the separation of the heavier, lower world of matter from the lighter, higher world of God. All the elements of matter will be part of the lower reality, though fire and air rise above earth and water.
Then later in the story, the creation of man takes place - in addition to the Logos sent down into nature earlier, a god of sorts has come into being who rules over areas of matter, and it has created seven celestial rulers (corresponding to seven planets in celestial spheres of reality), and "Men call their ruling Fate" (Mead, Poemandres, 9). The creatures which inhabit the lower part of the universe are created out of the basic elements, but they are "lives reason-less; for He did not extend the Reason (Logos) to them" (Mead, Poemandres, 11). This is the further continuation of the development of the dualism; reason only belongs to the "higher" creatures and levels of reality, and not to the lower, more physical areas. The actual creation of man takes place, and then man decides that he wishes to create just as the other divine beings do. So he is given creative power and some influence in the spheres of matter, but also must descend through the seven levels of reality controlled by the seven rulers all the way to the lowest level of matter, and he takes on a characteristic of each celestial level as he passes through. In so doing, he comes under the influence of those spheres and their rulers, and this is the origin of the control Fate will have on the lives of humans, and the foundation of astrology.
And once the nature of the dualism of reality has been established (higher reality is more mental, and has reason and power; lower reality is physical, has no reason and is ruled by Fate) and the human race has been bound to the control of the celestial spheres, the text introduces the opposite scenario: how to reverse the process. Poemander tells the narrator of how human beings can be re-ascend through the levels of reality, in a process that appears to take place in an afterlife, once the physical body has died:

When the material body is to be dissolved, first thou surrenderest the body by itself unto the work of change, and thus the form thou hadst doth vanish...the body's senses next pass back into their sources, becoming separate, and resurrect as energies; and passion and desire withdraw unto that nature which is void of reason. And thus it is that man doth speed his way thereafter upwards through the Harmony (Mead, Poemandres, 24-25).

On ascending through each level of reality, man sheds the influence of that particular level:

In the first sphere he leaves behind the ability to wax and wane; in the second the cunning of evil, from now on an ineffective trickery; in the third sphere, the deception of covetousness, which henceforth is ineffective; in the fourth, overbearing boastfulness, now a failure; in the fifth, frivolous audacity and rashness; in the sixth, evil desire for wealth, henceforth inoperative; and in the seventh, the malicious lie (Martin, 148-149).

And then he is free and can attain the highest levels of reality:

Then, stripped of all that lent the forces of the system of spheres their effect, man, who now possesses only his own strength, enters the Physis of the Ogdoad [the eighth level of reality, just below the ninth, the Ennead, which is where the ultimate Intellect/God dwells], and sings hymns of praise to the Father together with the creatures there (Martin, 149).

This is only barely touching the surface of the Hermetic view of reality, but it will serve as an introduction; the particulars of doctrine are explained in detail in other texts. But the two key themes - the dual nature of reality, and the eventual goal of overcoming the rule of Fate and rejoining the ultimate Mind in the highest "heavens" - are very clearly explained in those few fragments from the Poemander.

Hermetic Cults/Practices
While the major beliefs associated with Hermeticism can be deduced from the texts, it is harder to determine the practices or even the existence of actual Hermetic cults. It seems that this is an area where, true to form, Hermeticism offers a vast number of options. Two in particular are interesting, however.
One source speaks of the worship of Hermes in the Egyptian city of Hermopolis (Stock, 626), and Clement of Alexandria associated the Hermetic writings with Egyptian religion (Stock, 626). There is quite a bit of Egyptian influence in the Hermetic writings, as well as "respect shown to the Egyptian religion", leading one scholar to say, "that the author or authors were Egyptian does not require proof" (Stock, 627). This may be a bit of a stretch, but other sources at least concede that parts of the writings "bear the stamp of authentic Egyptian inspiration" (Mahé, 290). As for the practices of the Egyptian branch of Hermeticism, it is difficult to find many specifics - Clement once described a procession of (Egyptian) people in different professions, listing for each the specific Hermetic books that profession used or required knowledge of (Stock, 626), but the only real practices for which there seem to be definite evidence are those mentioned in the writings themselves - undoubtedly astrology figured into the system, due not only to the Hermetic books dedicated to it, but also to the prominence of Fate in the Hermetic belief system, and there is talk of a very Egyptian view of cult statues in the Nag Hammadi codex, where Hermes Trismegistus will not call statues the "truly living gods", instead saying that they are inhabited in a fashion similar to the traditional Egyptian belief in a spirit or ba which would act in a similar manner, and intimating that at some point in the future the Egyptians will cease to worship properly, and the spirits of the gods will depart from their cult statues (Mahé, 291).
Another interesting possibility for Hermetic worship lies at the other end of the spectrum from these Egyptian speculations: there may have been gnostic Hermetic communities. In one section of the Nag Hammadi codex, immediately following a prayer, there is a phrase - "Once this prayer was said, they kissed one another and went to eat their food that was pure and without any blood". This passage also occurs in the Asclepius and in a preserved Egyptian papyrus, and seems to raise the question of whether there were groups of Hermetic followers who engaged in certain practices like the meal described there. From this and other parts of the Nag Hammadi codex, Jean-Pierre Mahé concludes that such groups did exist: "Nag Hammadi codex 6.6 and 6.7 leave little doubt about it: indeed there were gnostics influenced by Judaism who invoked Hermes Trismegistus. They formed communities like the one described in Corpus Hermeticum 1.27-31, in which fraternal meals were held, the kiss of peace was exchanged, and initiations were conducted into the mystery of regeneration" (Mahé 291-292). The section of the Corpus Hermeticum to which Mahé refers describes the formation and teaching of a community of followers of Hermes Trismegistus under the leadership of the unnamed narrator of the Poemander (Mead, 6). Also, there is evidence that teaching communities of Hermetic followers did exist, and that this was a primary means by which the Hermetic teachings were spread (Williams, 691).
So there seems to be evidence for at least two different types of Hermetic worship: one group centered in Egypt, possibly around Hermopolis, which has at least some very traditional Egyptian beliefs, such as the nature of cult statues; and another type of group similar to gnostic or ascetic Jews, engaging in religiously-significant meals and other practices in communities. Given the wide scope and variety of the Hermetic writings and traditions, however, it is almost certain there were other groups, styles, and practices of worship, but a full investigation of them is beyond the scope of this project.

In a note unrelated to the purpose of this project and site, it should also be noted that there are still groups and individuals today who believe in and/or follow the Hermetic tradition, although many of their beliefs are based more on medieval and Renaissance-era extrapolations and expansions of Hermeticism due to interest in the nineteenth century and renewed interest towards the end of the twentieth century as certain New Age and related groups turned an eye toward Hermes Trismegistus and his writings. See the bibliography page for links to web sites of modern organizations which refer to or use the Hermetic writings or the figure of Hermes Trismegistus.