Lazarus wrote:I am studying seriously medieval astrology and am wondering if a malefic, especially in its fall or detriment, can actually harm another planet through what are typically regarded as benefic aspects (trines and sextiles). An example would be that a friend of mine has Saturn retrograde in Leo in very close trine to Jupiter in Sagittarius. So I'm wondering if this aspect should be interpreted as an ease of affliction from Saturn or if in fact instead Jupiter, strong in Sagittarius, actually could be interpreted as offering aid to Saturn.
If a trine is between 2 planets of short ascension, it might be regarded as a square and conversely, a sextile with signs of long ascension in between can be regarded the same way. This is stated in a couple of different texts (Paulus Alexandrinus and Manilius(?)). However generally a trine from malefics is not taken as hostile.
You might be missing something else in the chart such as a malefic with no dignity in the sign (not in any of its own places) or averse domicile or exaltation lords. Schmidt has said that such will trash the significations of the place they are in because they cannot effect from their own significations (which they could do if in any of their own places).
In your Jupiter / Saturn scenario you should be focusing on the topic. If Jupiter is the topic of finance then Saturn may be saying something about that topic. Because Jupiter is in its own domicile, it can effect favorably in this area on its own, but Saturn might add (old items) to the list of things owned such as antiques. So the answer is both ways, depending upon the topic. The topics ruled by Saturn are in worse shape than the ones ruled by Jupiter, but Jupiter may offer some bonification to the issues ruled by Saturn. The situation is better if the chart is diurnal.