Seven was considered a sacred and magical number among virtually all ancient philosophies and religions. The seven, also known as a heptad and septenary, is fundamental to understanding the occult doctrine. The importance of the number seven is rooted in the basic esoteric tenet that the One Boundless Principle in nature manifests as seven principles. These seven root principles are expressed in multitudinous ways, on all planes, in all kingdoms, and through all forms of life. The Pythagoreans considered seven to be the perfect number.

The numeral seven is a prime number that is the sum of an even and odd number. The dual, mystical nature of seven is shown by combining the three and four, as well as by adding one and six. In these expressions of seven, the odd number represents subjective male energy, fire, spirit, and light. The even number symbolizes objective feminine force, water, matter, and life. Seven is the number that blends opposites together in perfect balance and harmony. Occultism sees a seven-fold character evident in both the macrocosmic universe, and the microcosmic human.

Seven can be signified geometrically in many ways, including the seven-pointed star and the heptagon. Seven as three plus four is shown by an upward-pointing equilateral triangle aligned with, and hovering slightly above, a square. The triangle represents active invisible spirit; the square indicates the vehicle for spirit manifestation, or matter of different grades. This symbol connotes an upper spiritual triad emanating a lower physical quaternary, or matter being emanated from a spiritual First Cause. Seven as one plus six can be depicted in form by a six-pointed star or hexagon with an invisible central point. The unseen central point of the hexagon or star is the hidden source of the six visible points.

The universality of a septenary law operating in nature can be seen in every aspect of life. The seven basic principles are manifested through the seven heavenly men or Dhyan Chohans, in the form of seven color rays. Each color ray is sub-divided into seven sub-rays. The seven kingdoms of nature are each sub-divided into seven classes based on their occult properties. The cosmos contains seven energies, seven types of force, and seven grades of matter which manifest as the seven planes of life. These seven planes are each further divided into seven sub-planes. There are seven orders of crystals distinguished by their particular geometrical properties.

Humans are integrally linked with the number seven. The seven basic principles expressed through the seven rays are present in every individual. There are seven spiritual races of men, each divided into seven sub-races. Seven states of consciousness, seven personality types, and seven kinds of mind exist in the human family. Human beings progress physically and psychologically in seven year cycles. Every incarnated person has seven bodies, each with seven chakras. The human physical body contains seven major endocrine glands.

The ubiquitous number seven can be seen in the seven notes of the musical scale, the seven vowels chanted by Egyptian priests, the seven emanations of God, the seven breaths, and the seven sacred planets. Karma and Nirvana are two of the Seven Great Mysteries of Buddhist metaphysics. Seven is reflected in the seven lesser spirals of the atom, the seven lower Sephiroth of the Sephirothic Tree, and the seven dots that comprise the base of the tetraktys.