Part of the six-pointed star of humanity
One of two triangles from six signs forming a six-pointed star of humanity (see Capricorn-Aquarius-Pisces and Aries-Taurus-Gemini for further correspondences.)
Cancer–Capricorn
the slow rhythm of mass life—either instinctually active or the reactions of an imposed consciousness which is a result of chosen experience after initiation. It connotes mass life, leading to group life after the experience of initiation, for which its polar opposite Capricorn stands…
Leo–Aquarius
the sign of individuality and of self-conscious effort … group life […] finds full expression in Aquarius which completes the experience of Leo and fuses it with that of Cancer and Capricorn.
Virgo–Pisces
Gestation of soul awareness in Virgo, proceeding through labour in Capricorn, reaches birth of full human awareness in Pisces, able to give back to humanity what has been gained throughout the entire process of development.
This interlacing of the two above triangles constitutes what is called a triangle of humanity and… it concerns the relation of the individual to the mass of humanity and of the disciple to the group. […] It is the planet Neptune which is predominantly active in bringing about such an activity in Cancer that adequate momentum can be set up which will produce progress (through the intervening signs) to Aquarius. (EA 275-6)
Esoteric Astrology: 275-6