The Tenth Astrological House - Midheaven
The Tenth House: This place is also known as the midheaven or praxis, the greek word for work.  Because it is the highest point on the ecliptic for a given location, it represents authority. For most of us it shows us our attitudes toward and relationships with authority figures. It is interesting that this place is not associated with God as one would think (as the highest authority). My best guess is based upon two reasons. The 10th is very concrete in its manifestations, yet one cannot concretely prove anything about God. The other reason is that the 10th, Capricorn and Saturn have a natural affinity for eachother and Saturn is often associated with the devil and ignorance; that point beyond which one cannot go beyond, because it is too great. For this reason the midheaven also represents our highest potential, and our best achievements. The mountain top is symbolic of this. Saturn being excessively cold and dry shows what kind of conditions to expect at our peak. We will likely be very tired (indicated by the aristotlean quality of cold - inactive) and the dryness tends to separate us from eachother in the sense of putting you head and shoulders above another. For this reason it is considered to be a lonely place by nature, though through accident it can become more active and socially binding.
According to Dane Rudhyar, the 10th/midheaven is the height of the power axis.  Because it is the highest point (on the ecliptic) it is also one of the most visible areas of the sky. Political power comes from this visibility, as well as fame, social responsiblity, status and character. Here, the slightest mis-step is magnified many times over, and the higher the attainment, the more dangerous the fall. In other words, the bigger they come, the harder they fall. Morality and ethics play an important role here. The lord of the 10th and its cosmic condition show what honor and reputation the native is likely to attain as well as the nature of our work or profession. It cannot tell if one is a good person or not, only what the public perception is likely to be. Our actions are not necessarily our identity. This is a common pitfall of this place for many who believe that they are what they do.
According to Valens: "When the ruler of this place is well situated, it makes those who are effective; but when it is poorly situated, those who are unsuccessful.".  If unsuccessful, then one may try to succeed by dishonorable or criminal means. While I have not done much research on this yet, it stands to reason if the lots of theft, accusation or treachery or their lords fall in this place, especially without dignity then you may suspect that they do evil. There have been other examples of this kind of thinking; for example according to Valens: "If it (lord of the midheaven) happens to be upon the setting place and a malefic should be present with it, or make a diameter (opposition), it makes evil-doers..." 
If we look at this place from a cyclical perspective, we see that the 9th, which represents learning, is put into practice in the 10th house. Here is where your dreams (9th) are actualized (10th). It is also the school of hard knocks, because there is no turning back from decisions made here. It would make no sense to turn back because this is the point of no return. Related to this idea is that this place gives signs relating to conditions at midlife. This is because sunrise represents birth, and sunset represents death, and the midheaven is halfway between the two.
More info on each of the planets that have dealings with this place:
44. Paulus Alexandrinus, Hellenistic astrology Introductory Matters 378 A.D. © 1993 Robert Schmidt, through Project Hindsight, Published by The Golden Hind Press. See pg. 56. Schmidt translates the word from the greek "praxis" meaning work.
45. See note 21.
46. Vettius Valens. Anthology, Bk II, Part 1. aprox. 160 A.D. © 1994 Robert Schmidt, through Project Hindsight, Published by The Golden Hind Press. See pg. 11.
48. Ibid, see note 44 above, substitute pg. 57.
52. Ibid. See pg. 56.
53. Ibid. See pg. 57.
54. Ibid. See pg. 58.
56. Ibid. See pg. 56.