It is connected to the Ajna Center and it's harmonic gate is the 63rd gate. The 63rd gate, the gate of Doubt, shares its doubt while the 4th comes up with a solution. Together they form 63-4, the Channel of Logic. The 4th gate is in the constellation of Leo. This can be recognized in Leo as it is a youthful sign in the zodiac. Those born under Leo tend to be playful, theatrical, dramatic and, like children, they like to be in the centre of attention. They want it to be seen that they come up with solutions.
Quote from Incarnation Crosses by Profile (Jovian Archive 2008).
"When we're looking at the 4th gate we're simply looking at a gate of formulas, a gate of formulas to try to deal with the pressure of doubt, doubt about the pattern. And the first thing to be clear about is that through the 4th gate, the doubt about the viability of any relationship is the key.
There is no future for humanity unless we can make more. There is no future for humanity unless we have pair bonds that manage to last long enough so that the young are nurtured long enough so they can stand on their own and survive, that it's clear in the pattern of the way in which we operate that we are conditioned to be with the other through the pattern into the future. And what the 4th gate wants to be able to do is it wants to be able to come up with a formula that makes it acceptable to spend your life with somebody that you can never be one with."
Ra Uru Hu