To believe (something is reasonable) and argue (for it); to advocate.
To be in opposition; to contest; to dispute; to vie; to quarrel; to fight.
To be in debate; to engage in discussion; to dispute; to argue.
To struggle or exert oneself to obtain or retain possession of, or to defend.
contend with: To try to cope with a difficulty or problem.
To deny the truth or correctness of (something).
To prove (something) to be false or incorrect.