One part of astrology that confuses many newcomers (and some more experienced practitioners) is the uses of the Arabic Parts or Lots. They are often dismissed by more modern astrologers as superfluous which is mostly due to the sheer number of Lots in existence. Arabic sources cite 128 different parts, while Guido Bonatti lists that they are 143 in number. In reference to the Parts, Al-Biruni is quoted as saying that “they increase in number daily”.
The amount of Arabic Parts appears overwhelming at first, and it is this initial introduction to the vast army of Parts that leads many astrologers to dismiss them in similar logic as they usually dismiss asteroids as astrological bodies. This analogy stings some, as obviously the Parts were being used in traditional texts and may have been used as far back as 300 BCE which is an obvious difference to the asteroid culture that has been in effect in roughly the past 30 years. This leads to such questions as which Parts may we use and may we not use which itself comes down to circumstance.
Arabic Parts are mostly used in horary astrology to fine-tune answers, especially when the primary testimony (the conditions of the planetary significators) is vague, confusing, or dubious. Generally you look for the condition and placement of Parts that are relevant to the question. The Part of Barley would obviously not be relevant to a question concerning a relationship, but the Part of Marriage may be depending on the particular question.
Natal astrology is where picking through the Parts is essential, as there is really no one question that the entire chart is oriented towards answering. A natal chart is describing the entire life of an individual, and all of the Parts there are now are up in the air as being important. Luckily, ancient astrologers had an idea on how to trim down on this seemingly overwhelming amount of prognostication material. In order to be ‘activated’ a Part cannot fit any of the following criteria: 1) afflicted, 2) ruler is afflicted, 3) none of its rulers aspect it.
Planets are afflicted if they are Combust, in a cadent house, retrograde, or harshly aspected by a malefic planet. Robert Hand says that a part being Cadent is not – in itself – capable of afflicting it, but it is capable of afflicting a ruler of a part. So, a Part is not activated or important in a native’s life if its dispositor is afflicted by being in a cadent house, in retrograde motion, Combust of the Sun, or afflicted by a malefic planet. It is also not activated if none of its rulers aspect it, ‘none of its rulers’ refers to the planet that rules the sign the Part is in, the exaltation lord, all three triplicity lords, lord of the term, or lord of the face. Keep in mind though, that a Part itself may be deactivated by being Combust of the Sun or afflicted by a malevolent planet.