Father and son

Another theme at the heart of 'There Will Be Blood' links to this, that of fatherhood. The idea of being a good father is central to Daniel's view of himself. He openly shows love for his son H.W. Plainview (Dillon Freasier), referring to him as his business partner as well as his son. Check this out below:

https://www.maketheswitch.com.au/article/feature-there-will-be-blood-celebrating-the-15th-anniversary-of-an-american-masterpiece#:~:text=Another%20theme%20at%20the%20heart,as%20well%20as%20his%20son.