The sesquisquare aspect or sesquiquadrate aspect as it is sometimes known as, is where two planets are one hundred and thirty five degrees apart. This is like a square aspect of ninety degrees combined with a semisquare aspect of forty five degrees.
Indeed the themes are very similar to both of these. Here there is a difficult link between the planets so also there is a difficult link between two attributes of the psyche. This difficulty is likely to spur the individual to greater heights in their efforts to achieve some kind of balance and harmony. With these efforts they should go on to achieve tangible results in the world although the path will not be easy.