Brahmin means not caste but one who has attained Atma Jnana or Brahma Jnana.

In Vedic era a Brahmin was a person who had attained Self- knowledge or Atma Jnana. This was an extremely difficult path of discipline of body, mind, and intellect, and people irrespective of their birth or class, who dedicated to such an austere life, were recognized as Brahmins. 

A great example of this tradition (that a person becoming a Brahmin, rather than born as one) is the case of Vishwamitra, a warrior (Kshatriya), who became a Brahmin after attaining Atma Jnana or Self-Knowledge.

 Smritis, or code of conduct composed by sage Atri defines brahminhood very clearly.

"By birth, every man is a Shudra (an ignorant person). Through various types of disciplines (samskaras), he becomes a dwija (twice born). Through the studies of scriptures, he becomes a vipra (or a scholar). Through realization of supreme spirit (brahmajnana), he becomes a Brahmin."

The belief that people born in Brahmin caste, automatically become Brahmins, is a much later concept in the very ancient India.  Thus, Brahmin means not caste, but one who has attained Atma Jnana or Brahma Jnana.  

Blind beliefs without verification and argument and interpretation on the base of the false self are not verified knowledge therefore it is not truth.

v  What is the use of arguing on base of the birth entity, which is not the self?

v  What is the use of knowing what happens after death when the self is birthless? 

v  What is the use of thinking of the heaven and hell when the self is not an individual and it is never born and never dies?

When formless consciousness, is the innermost self, which pervades in everything and everywhere in all the three states, what value the theoretical philosophies and scientific inventions   which are based on individual intellectuality will have.  

The consciousness is ultimate truth or Brahman. Consciousness is the ground of the universe, the consciousness is the first cause of the universe and it itself is uncaused. 

Ultimate truth cannot be defined in positive terms because any definition would mean limitation.  One has to realize the fact that, the universe and all its contents are mere mirage created out of consciousness.  That means the mind and the soul, which is the innermost self are one in essence.