Yantra – a symbol of cosmic consciousness

I started reading Yantra:The symbol of cosmic consciousness by Mukesh Khanna. Its a pretty interesting read and shows how advanced Indian thought actually was. I will present a review of each of the chapters of the book as I go through. 
Om

उपोद्गात

Dhriti: The mind's ability to process and store what it has learned.
आतिन्द्रः सन्ग्रः सर्गो ध्रितात्मा नियमो य़मह्
इन्द्रियानि मनो बुदः सत्वम् तेजो बलम् ध्रितिः