The tripartite principle of thought.
Just as matter manifests itself in three states: solid, liquid, and gaseous, time also manifests itself in three forms: becoming, duration, and chronometry. Becoming is the flow of time that goes from the past to the future passing through the present. It is perceptible. Duration is the interval between two sequential moments. It is subperceptible because we see the moments separately, one before and the other after. Chronometry is the measure of time. It is intelligible. These three time states coexist in a clock. Also in the parallelochron the three states of time are represented.
Other examples of the tripartite principle of thought are: God, with the Father, the Son, and the Holy Spirit in religion. The conscious, the subconscious and the unconscious in Psychology. In state government we have three branches: Executive, Legislative and Judicial. In philosophy, knowledge has three forms: concept, judgment, and reasoning.