If you want to be a thinker, highest thinker, think in terms of Bhagavatam or Bhagavad- gita. Have input from Gita and Bhagavatam, you will be the best thinker, the topmost thinker of this world.
Scriptures are also called ‘Grantha-ratna’. The deeper you dive, the knowledge you will discover will be most precious, cause that gemstone is Krsna Himself.