Jungian level (Psychological Principles):

Mercury governs the processes of thought and communication, represents our capacity for perception, insight, and the awareness of sensory input. Mercury governs the ability to perceive, conceptualize, and articulate; to employ words and language; to acquire knowledge, analyze, comprehend, and teach; to move, transport, and exchange. This archetype is manifested through our inherent capacity to teach, transmit, and share information with others. The negative expression of this archetype includes a one-sided point of view, detachment from human emotions, heightened nervous tension, and excessive verbal expression. A major aspect involving Mercury and another planet often speaks to an individual’s mental processes or neural functioning and the manner in which they give and receive information.