If a seed is planted in the earth and watered, in a day or two it will drink in the moisture and swell in size. The sprouting has not yet taken place but the first change is this. The Mahat-tattva is a happening of this type. Next, in accordance with the will of the Lord, a sprout arises. That is called Mahat ahamkaram. From it, five leaves break forth, the subtle principles of the Five Elements. The entire Jagat is the combined product of these eight:Prakriti,Shakti, Mahat-tattva, Ahamkaram and the Five Elements or Pancha bhutas. (GV, p. 103)
There is the Mahat-tattva, which is the body of the bird of Buddhi. Mahat-tattva signifies the realisation of the Mahavakya, ‘Tat Tvam Asi – the great Upanishadic declaration, That Thou Art’. In other words it is experiencing one’s real Self as Sat-cit-ananda. Buddhi should not therefore be confused with Medha, which refers to the possession of worldly talents, intelligence and cleverness etc., without having Self-knowledge. Thus Buddhi consisting of Shraddha,Satyam,Ritam, Mahat-tattvam and Yoga may be considered as the resound, reflection and reaction of the Atma. On the other hand, Medha-Shakti – the power of worldly knowledgs – corresponds to Maya- Shakti, the divine power of delusion. (ICS , p. 95)