Sexuality in human beings according to Human Design is based on two fundamental themes. One that is the domain of the Sacral Center and the other the Solar Plexus Center. In the Sacral Center, we have availability. Availability is going to be the theme that we're going to look at in this segment. On the Solar Plexus side, we have drive.

So, we have these two things. We have sexual availability, sexual availability is in the Sacral Center, and then its binary—everything is a duality, everything works through dualistic tension—in the Solar Plexus Center is the sexual drive. That is, the sexual drive that is driven by need, by passion, and by desire, which are the three Streams that operate through the Solar Plexus Center.

What we're looking at is the availability. Now remember that in terms of the biological relationship of the Sacral Center, in terms of the way in which we relate Centers to biological functions within the body, the BodyGraph, that in terms of the Sacral Center, we're dealing with the testes and the ovaries, we're dealing with the sexual organs of the male and the female. So, we're dealing with the deep procreative capacity of humanity to regenerate itself. And regeneration is one of the most dynamic themes in the Generator’s life.

But we've also seen that the very nature of the Sacral Center is that it only operates out of response. In other words, this is the way in which the Sacral Center is intended to operate. And this concept or theme of availability, is that this can only be recognized through response. In other words, given the Gate that you have in the Sacral Center, you're going to express your availability by responding through that Gate, and only through that Gate. Again, dealing with the limitation of being fixed.

Excerpt from Sex and the Generator

Ra Uru Hu was the Human Design System’s founder and messenger. Ra dedicated 25 years of his life to the development and teaching of the System around the world until he passed away in 2011.