In Biblical Hebrew, the letter vav also possesses the function of inverting the apparent tense of a verb to its opposite from past to future or from future to past. The external force of the line is the power to differentiate and separate the various aspects of reality, thereby establishing hierarchical order, up and down, within Creation. The internal force of the line is the power to reveal the inherent interinclusion of the various aspects of reality, one in the other, thereby joining them together as an organic whole.