Chokmah, is pure force. Hence its on the pillar of mercy, mascilune one. Binah is the form. It gives shape into the force, but with form, comes death. Thats why its on the pillar of severity, the feminine side. We have 3 pairs like this.
Chokmah - Binah
Chesed - Geburah
Netzach - Hod
The two lower pairs, I need more study to explain, but Chesed is like a wise old king while Geburah is the conquering one. Netzach is emotion while Hod is pure intellectual thought, etc ad infinitum.
Every upper sephira carry within the potential of latter sephira. Kether therefore, while carrying form and force, its not manifested yet. The title given it is Crown. Its something immediately above the head. One meaning of this being Kether is of but not within the manifest cosmos, probably. One title given to it 'The Head Which Is Not', hints at it.
Anyways, this info is useless if not applied. Looking at you, Middle Pillar.