Teachings of rishis are nuanced. Whether Jyotisha, Mantra Shastra, Tantra, Ayurveda or Vastu, thumb rules go only so far. The key is to derive & digest the FIRST PRINCIPLES & apply them intelligently! Let us take Vastu, which is becoming popular. Most contemporary application is unfortunately thumbrule-driven. Let me give one simple example. Per thumbrules, southeast direction is bad for a child's bedroom. Southeast (aagneya) emanates the energy of Agni (fire). That extra fire affects the constitution of a child who spends most of his/her time in a room in that direction. It can make him/her rebellious, which may not be desirable. That may be the logical basis of that thumbrule. However, what if a child is too soft, dull, lazy & not driven at all? Perhaps southeast is actually GOOD for such a child! I actually know of a real example where a teenage son was moved to the southeast bedroom & there was noticeable positive improvement in his life after that move! He had more energy & drive & was less lazy & dull. * * * Most modern books on Vastu take the thumb rule approach. Very few actually try to get to the first principles & take a nuanced & holistic approach instead of laying out rules in black & white. One such nouanced book is by Dr Robert Svoboda: "Vastu: Breathing Life Into Space". I recommend reading & digesting it. * * * Another example of mindless thumbrules used in arsha vidya: Some Jyotishis use thumb rules like Venus dasa giving marriage, luxuries & pleasures or Saturn dasa giving hardships, setbacks etc. Discerning Jyotisha students know that it doesn't always work like that - it depends on the chart. For example, there are people who became Prime Ministers & Presidents in Saturn dasa! In my own Saturn dasa (and Saturn is in the dreaded 8th house in my chart, along with 3 other planets!), I passed 2 exams equivalent to BA in Sanskrit at the ages of 11 & 12 (Sanskrita Bhasha Kovida & Sanskrita Bhasha Visharada), won prizes in state level elocution & chess competitions, stood state first in 12th grade, went to IIT-M, stood second in class there & went to US after that. It was a pretty positive dasa! * * * Arsha vidya is nuanced & we can't just go by thumbrules. We MUST derive & digest the FIRST PRINCIPLES & apply them intelligently.