Did someone say pagan? 
Want my quickie pentacle lecture? As LifeOnWry says, this is The World According To Me (and some, but not all, other neopagans), because nothing is agreed upon by every one, including that.
Both pentacles, the “upright” and the “inverted” were described back in 1855 in Eliphas Lévi’s Dogme et Rituel de la haute magie, long before Wicca was a gleam in Gardner’s eye. Lévi described the one-point-up as “when one point is in the ascendant, it is the sign of the Saviour.” and two-points-up as representing “Satan as the goat of the Sabbath”. The symbol, or some form of it, was then used by Freemasons, and by the Church of Satan for internal work in the sixties and made public in 1968. It continues to be so used today, with the head of Baphomet on it. Any neopagan, Wiccan or otherwise, who says that an inverted pentacle doesn’t mean something Satanic at all, ever, is just plain wrong. It means that, and it meant that first.
It may not mean it to the person wearing it, however. Symbols change and reasons change. The Nazis weren’t using the swastika as a sun symbol, and so it became a symbol of hate - except in Hindu societies, where it’s still a symbol of life and rebirth. Here is the way the pentacle is perceived and used now by many neopagans, including Wiccans (according, again, to me.):
The five points of the pentacle symbolize the five elements we hold important (some would say “sacred”.) Four of these are probably familiar: air, earth, fire and water. Each element is associated with, or reminds us, of different parts of ourselves, different qualities of being, different colors – pretty much anything than can be categorized can be done so in an elemental system. Air stands for the intellect, inspiration, yellow and purple, things that are warm and moist. Water for emotions, spring, blue, things that are moist and cold. Fire stands for will and power, red, things that are warm and dry. Earth stands for manifestation, “groundedness”, green and brown, things that are cold and dry. If one of these is out of proportion, a person’s life will tend to go out of balance. Someone with too much emphasis on inspiration (air) who does nothing to make their ideas manifest (earth), is going to be unhappy that nothing ever comes of his ideas. Someone focused on making money (earth) to the exclusion of their emotions (water), is likely to end up lonely and unhappy.
Four of the points of the pentacle represent each of the four classical elements in perfect balance - each of the same size, none predominant. The fifth point is representative of Spirit. Most neopagans who wear pentacles, most of the time, wear the Spirit point up, a symbol that we set Spirit as most important, most of the time. Spirit leads, the elements are used in service of the Spirit - they are literally beneath spirit in the symbol.
It is occasionally the case that a neopagan might be doing a specific kind of magickal work to increase the influence of one or more of the elements in their life. This, ideally, IMHO, should be a temporary thing. If I were to do magick to lose weight, for instance, I might want to increase my fire (willpower) and my earth (power over solid earthly objects, like my giant ass) energies. In this case, I might (as part of a larger working) wear a pentacle with the fire and earth points up - which looks like an “inverted” or “upside down” pentacle. I’d want to be very careful not to overdo it. When I feel like those elements have been strengthened sufficiently, I’d put Spirit back on top.
So it’s not true at all that “good witches” never wear an inverted pentacle. We do, some of us. We’re just less likely to let you see it, lest we have to go on the defensive when y’all see it as further evidence that we’re unwittingly worshiping Satan.
(The Church of Satan (nice folks, by the way. Have way more in common with most of the most vocal Dopers than I think they’d like to admit. See LeVay’s short essay on Pentagonal Revisionism if you don’t believe me.) uses an inverted pentacle in the Sigil of Baphomet which makes its goaty connections very clear.)
