The placement of Mercury in Scorpio indicates you have a need to function at a deep mental level with authenticity and integrity. Much of the behavior and many of the personality characteristics associated with Mercury in Scorpio are a result of this need to mentally perceive the truth about yourself and your environment. Mercury is indifferently placed in Scorpio. The positive aspects of the placement are symbolized by the natural sextile between Scorpio and Mercury-ruled Virgo. However, Scorpio is the Fixed Water sign and both fixity and water are problematic for the air and mutable-associated Mercury, as symbolized by the natural quincunx between Scorpio and Mercury-ruled Gemini. 

The Fixed Water of Scorpio pulls the mental energies associated with Mercury to deep places, from which escape to the outer world is difficult. In these deep places, the Mercury-associated functions gain power through access to reality and truth. However, Mercury’s air is challenged to adapt to the flow of Scorpio’s water.  The Mercury functions are naturally more comfortable in the realm of the ordinary and the everyday. 

Mercury’s placement in Scorpio suggests that there are certain personality characteristics and qualities with which you identify. Typical Mercury-Scorpio qualities are listed below, with positive qualities listed first and their more negative, or dysfunctional, counterparts listed afterward. These qualities are divided into three categories, corresponding to major Mercury-symbolized functions: intellect, communication and the nervous system.

Insecurities

With Mercury in Scorpio, if you are insecure, your mind is obsessed with being dominated by forces beyond your control. At its extreme, this can turn into a paranoia-like fear. In order to “protect” yourself from being dominated by other people, you constantly search for ways to dominate them. This mental preoccupation with power and control eats away at you and makes you suspicious and fearful. 

Mercury in the 2nd House:

With Mercury in the 2nd House, the Earth influence associated with the 2nd House suggests that your mental energy is practical and grounded. It is likely that your mental energy will be turned toward matters associated with physical survival and providing for comfort and financial security. More abstractly, you may turn your attention to forming values. However, having Mercury in the 2nd House, if you do not consciously reconsider your value system, then it is likely that you will not deviate from the value system to which you have been conditioned - one that is dominated by material values and self-interest. 

As an individual with Mercury in the 2nd House, much of your mental energy is likely to be occupied with material acquisitions and securing a safe and comfortable environment for yourself and those who depend upon you. You may always be thinking of how to provide for your and your family’s material security. Because of this focus, with Mercury in the 2nd House, you may be more likely to have a cautious and practical mental attitude. You are likely to view intellect as valuable when it is useful in pursuing your goals. You may have some antipathy toward those "intellectuals" who are concerned with less practical matters.