"It is a symbol which Solomon conceived once To betoken holy truth, by its intrinsic right, For it is a figure which has five points, And each line overlaps and is locked with another And it is endless everywhere, and the English call it, In all the land, I hear, the Endless Knot." Poem of Sir Gawain and the Green Knight

A pentagram, a five-sided star, constructed by intersected five straight lines, is one of the oldest markings known to humanity. It is a symbol fraught with mystery, intrigue, and meaning. It is also called a pentacle or Pentalpha, and gets its name from the Greek penta, meaning “five” and gramma, meaning “a letter”.

The pentagram was apparently discovered by astronomical research in the Tigris-Euphrates region of the Middle East, as far back as 6000 B.C.E. Mesopotamian writings showed the first use of pentagrams. Sumerian pictograms were used to depict the word “ub”, meaning a small nook and cavity. Pentagrams have been found in Israel, in layers dating to 4000 B.C.E. It has been discovered amongst the Sumerians, with the five points believed to represent either the four corners of the earth and "the vault of heaven," or the five visible planets of the night sky: Jupiter, Mercury, Mars, Saturn, and Venus (with Venus a representative of the Queen of Heaven, as Venus traces an almost perfect pentagram across the night sky every eight years).

In Ancient Greece, the symbol was of interest to Pythagoras, who believed that the pentagram was a symbol of perfection. He called it the Pentalpha, because he noted that it was comprised of five geometrically perfect As. In his world travels, it was believed that he had influenced other cultures, and the current theory is that Pythagoras is the reason that the Pentagram shows up in Tantric art. In many cases, early Hindu and Buddhist writing shares the same symbolism as that which Pythagoras has written. The Pythagoreans were driven underground and used the pentagram to identify themselves to each other, signing letters and communications with it. During this time, the pentagram represented the five points of a human being: Two feet, two hands, and one head, although this seems to underestimate the knowledge of the Pythagoreans, as they were almost undoubtedly aware of its mathematical properties.

The Pythagoreans called the pentagram, ύγιεια Hygieia meaning "health" (also the Greek goddess of health, Hygieia), and saw in the pentagram a mathematical perfection, as the pentagram divides itself automatically in accordance with the Golden Ratio.

In mathematics, the Golden Ratio, often represented by φ, denotes the non-repeating, non-terminating number 1.618033988… Two quantities are in the Golden Ratio if the ratio between the sum of those quantities and the larger one is the same as the ratio between the larger one and the smaller. Each intersection of edges sections the edges in Golden Ratio. The ratio of the length of the edge to the longer segment is φ, as is the length of the longer segment to the shorter. Also, the ratio of the length of the shorter segment to the segment bounded by the 2 intersecting edges (a side of the pentagon in the pentagram's centre) is φ.

During the times of the Hebrew Scriptures (Old Testament) the pentacle was the first and most important of the Seven Seals – an amulet whose seals represented the seven secret names of God. It was inscribed on King Solomon’s ring, which is often, in error, called Solomon’s Seal. Each point of the pentagram was also interpreted as referring to the five books of the Pentateuch – the first five books in the Hebrew Scriptures; the Torah.

To the Hebrews, the five points of the pentagram were tied to the Pentateuch (the first five books of the bible) and represented as a whole, the concept of truth The Celtic Druids seemed to believe that the pentagram was a representation of the sacred nature of five. It was common that the pentagram was also a symbol for the underground Goddess, Morrigan. Interesting to note that much of today’s neo-pagan movement is based on remnants of the old Celtic traditions and symbols. In Nordic countries, the pentagram was used to ward off trolls and evil in general and was drawn on doors and walls. There are also many connections between the pentagram and Christianity. Before the cross, it was a preferred emblem to adorn the jewellery of early Christians. It has represented truth and has acted as a medieval talisman. The pentagram was associated with the five wounds of Christ and because it could be drawn in one continuous movement of the pen, the Alpha and the Omega as one. It also represented the five virtues: generosity, fellowship, purity, courtesy and Mercy.

Constantine used the symbol on his seal and amulet. It has been referred to as the Star of Bethlehem. It symbolizes the star that led the Zoroastrian astrologers to baby Jesus. Some also theorize that the pentagram was an expression of an early, secret Gnostic heresy, found hidden here and there throughout Christianity's history, a symbol of Isis/Venus as the "secret goddess," or female principle. This symbolism commonly shows up in the Arthurian Grail romances, which many see as Gnostic teachings disguised as knightly quests and their tales. The pentagram was embodied as a symbol of this feminine principle by the five petaled rose, found in many gothic cathedral ornamentations—they are truly subtle though not quite secret pentagrams. It has then re-emerged as a sign of humanism. It signifies man’s relation with the cosmos and also is seen as a guard against evil. Heinrich Cornelius Agrippa created a pentagram aligned with the shape of a man inside of a circle. Here the pentagram represented the Universe, and the five points aligned with the figure of the man represented jointly the parts of the body and the planets. Unlike previous ancient lore from Sumer, the planets changed alignment on the pentagram: Mars was at the head and top point, Venus to the left, Jupiter to the right, and Mercury and Saturn at the bottom. With the single point upward, the pentacle came at this time to symbolize the universal human, with the points aligning with the head, legs, and arms. Due largely to Agrippa and Leonardo da Vinci, the pentacle represented not only the human aspect but the creative spirit that lifts people away from the physical world to the spiritual world.

Christians of the renaissance were especially enamoured of the pentagram, which they viewed as a mystical proof of the divinity of Christ – to them, it symbolized Christ as the Holy Spirit manifested in the flesh. A favourite gematric feat was to add the Hebrew letter Shin (symbolizing fire and the holy spirit of Pentecost) to the Biblical four-letter name of God YHVH yielding YHShVH- Y’heshu or Jesus. Renaissance-era ritual magicians used the Pentagram as a microcosm of the human body. The practice of Ritual Magic was used to create a state of closeness with god through the use of symbols and rituals to imitate the divine state. It was believed that like affects like, that the connection between the world of symbols and the world of actions could also be manipulated for evil purposes. One of these magicians, Giordano Bruno, warned of such misuse of the powerful pentacle by Black magicians. In the Jewish kabbalistic tradition, which borrows many Pythagorean ideas, the pentagram represents the five upper sephiroth on the Tree of Life. Five numbers, being indivisible by any but themselves, which represent pure archetypal forces: justice, mercy, wisdom, understanding, and transcendent splendour.

Today, the pentagram’s religious symbolism is commonly explained by reference to the neo-Pythagorean understanding that the five points of the pentagram represent the four elements (earth, fire, air, water) with the addition of Spirit as the uppermost point.

As a representation of the elements, the pentagram is involved in the Wiccan practice of summoning the elemental spirits of the four directions at the beginning of a ritual. The outer circle of the circumscribed pentagram is sometimes interpreted as binding the elements together or bringing them into harmony with each other. It is a cliché within occult circles that the pentagram, when one point is rising, is a symbol for the positive principle, and when two points are ascendant it is a symbol for the negative principle. This is consequent from a claim that the direction of the rays of the pentagram establish if it represents the good or evil principle: one point up representing order and light, two points up representing disorder and darkness. The point down pentagram indicates the individual (microcosm) in a "Solar orientation", meaning not "earth oriented”. No known graphic associating the pentagram with iniquity appears until the nineteenth century. The Inquisition of the early 1300s does not appear to have made a connection between the pentagram and the Knights Templar’s assumed reverence of the Baphomet. It is only in the later twentieth century, and the foundation of the American Church of Satan, that the inverted pentagram has become a accepted symbol for Satan.

Satanists use a pentagram with two points up, often inscribed in a double circle, with the head of a goat inside the pentagram. It is called the Sigil of Baphomet, the God of fertility and reproduction. The term may have come from two Greek words, baphe and metis, meaning "absorption of knowledge." It has also been called the Black Goat, Devil's Goat, Goat Head, Goat of Mendes, and Judas Goat. Its first appearance appears to have been during the sadistic interrogation of members of the Knights Templar by the Christian Inquisition. The Pythagorean Greek letters are most often replaced by the Hebrew letters לויתן forming the name Leviathan. Less esoteric LaVeyan Satanists use it as a sign of rebellion or religious identification, the three downward points symbolizing rejection of the Holy Trinity. Possibly due to this the pentagram later became associated with Satanism and subsequently rejected by most of Christianity sometime in the twentieth century.

However, within traditional forms of Wicca, a pentagram with two points up is associated with the Second Degree Initiation and in this context has no relation to Satanism.