the gemini cancer cusp

The question asked where Gemini becomes Cancer: Is language magic?

Every fourth sign is Water. Water is Mystery. Cancer turns the empty binarism of Gemini into an infinitude of possibilities, symbolized by the pair of comedic, unpredictable pincers. Cancer turns the rational geometry of Gemini’s parallel into the double helix of DNA. One can run with this metaphor. For instance: Gemini rules the pair, the male and female gametes, Cancer the resultant pregnancy and birth. Gemini is the pure information of letters and digit, the empty on/off; Cancer is the fertile imaginative capacity that transforms that information into human meaning;  the book vs. someone to read it.  Each fourth sign in the zodiac is a water sign, following an air sign. Air is rational intellect, water irrational emotion. Thus the zodiac proclaims that rationalism is invariably superceded by something mysterious, involving love and death. But these ruminations add nothing really to what’s already in the literature. For instance, in C. E. O Carter’s classic:

“To those who are chiefly developed on the mental side, as is so often the case in the modern world, the passage from Gemini to Cancer seems a retrogression. After attaining the keen if limited mentality of Gemini, what a fall it seems to pass back to a sign that is largely instinctive and has the reputation of wallowing in emotion, especially of the gloomier kind!”
                     Essays on the Foundations of Astrology, 1947