Every object in the world creates and radiates a certain kind of aura and vibration which is unique for that specific object. Flowers radiate positive vibration and happiness and thorns and thorny objects cause discomfort to eyes and the mind too.
This is the basic concept of vastu for keeping objects and stuff in the house. The objects that radiate positive feelings, good thoughts and inspiration are assumed as positive. Things keeping and decorating the home just as images of flowers, orchard, fish, swastika, Kalash, mountain, horse, stream, river etc. They create happy feelings and thoughts.
The objects that create negativity, sadness, struggle, hardship, are assumed negative stuff for vastu point of view. Pics of dangerous animals like lion, hyena, images of war, desert, draught, dry tree, etc are some examples of this.
But, there is no hard and fast rule for that. Our sages have given the crieteria of place, time and situation (Desh, Kala and Parishiti). Different cultures and communities visualise things in different ways. At some places, cat is viewed as being inauspicious but some communities assume it to be very auspicious. Keeping and decorating home with sword is very auspicious for a warrior clan but not positive for normal households.
Some communities keep thorny plants near the main entrance to filter out negative vibes. On the other hand, some view thorns to be very negative. In some situations snake is good, but it is not so good in other situations. So is the case with the picture of a lion or a tiger. If associated with goddess Durga it is good and holy, otherwise not good. If a person’s occupation is related to research on wild animals, pictures of lion are not so bad. So, desh, Kala and paristhiti are very important.
Let us have a look at the holy text of the Mahabharata. Many vaastu counsellors propagate the view that keeping the book of Mahabharata is very inauspicious as it creates the vibration of tension, struggle, quarrel etc. Many a people avoid to keep this book at home. But this is only a wrong notion. Such persons (who propagate such views) indirectly play a negative role and hinder our cultural understanding.
Nowadays, many people (who assume themselves to be modern and updated) keep a lot of books related to thrill, fear, crime, lust, sexuality at their decorated and illustrative showcase and bookshelves. Such books definitely create negative vibes. There can not be two opinions about it.
Is Mahabharata a war book? The answer is a big NO. This holy text is related to dharma, Artha, Kaama and Moksha. In short, the complete depiction of the human life. Sage Vayas himself stated so. People like to keep Shrimad Bhagwat Gita at home and love to chant and listen to Vishnu Sahasranam Stotram.
These two great texts are compiled nowhere but in the Mahabharata. Keeping and studying this holy text enhances the sense of humanity, virtue, wisdom, spirituality, practicality and the knowledge of past. The great discourse of Bhishma ,Vidur Niti, Anugeeta etc are also there. There is shanti parva also.
So, no negativity is associated with this book. The Ramayana, the Mahabharata, the Puranas etc. are very rich sources of positive thoughts and vibration. Many scholars, writers, researchers, sages and historians have these books in their home book collections.