The Fours represent solidification and manifestation and are attributed to Chesed (mercy). The fours are "below the Abyss" and express the Rule of Law (Laws of Physics etc.)
The Four of Wands is called Completion, as the manifestation promised by Binah (understanding) has taken place. The Four is a very solid number as it has dominating influence on all the cards. The Masculine nature of fire permits the Four of wands to be clear cut and concise in nature.
The Four of Cups-Pleasure, is watery, and thus less concise, there is a natural weakness in water (to take on the impurities of its environment) that threatens its purity; it is not quite strong enough to control itself properly. This makes Pleasure a little unstable as the process of satisfaction has made it impure. Pleasure is thus known to be fleeting.
The Four of Swords is called Truce and represents a Strong union of Spirit-Unconscious, Conscious and Sub-conscious union that is a strong bond that keeps the manifestation in peace.Since Swords are Air (Consciousness), they are a masculine dominant force much like a military clan system of a society. Consciousness, is as Air, and is a flowing, electric force.
The Four of Disks is called Power, and its very solid nature pretty much eliminates any consideration of weakness. This is the power that dominates and stabilizes everything by pacific and negotiated methods, rather than by assertion itself. It is the Law, the Constitution without an aggressive element. Much like magnetism, which holds everything together without a destructive side.
The Fours a balance, solid, and show a good foundation. The Four of Cups is the "weakest" card of the Fours, because of the nature of Satisfaction from Pleasure. ----it doesn't last long as satisfaction is very emotional in nature and is disturbed by the environment around it. Dissatisfaction, soon rears its dark head, and the Pleasure seeker must seek something new.
The Four of Wands is Fiery Motion contained by the Magnetic Force of Binah....we are all "alive" because of this containment of Electric force.
The Four of Disks, is the Fortress of Matter itself, the strong bond between atoms and molecules creating a "solid foundation".
So when the Fours show up in a reading....they set a positive president to the layout, and because of their strength,tend to null the negatives around them. The only exception being the Four of Cups, whose nature is polluted by its surroundings. Thank you for your interest and comments. May you live long and prosper!