A Crank, as defined by Martin Gardner in his book In the name of Science
#1 The Crank considers himself a genius...even a towering genius who is years ahead of his time
#2 He considers his colleagues and fellow researchers "ignorant blockheads" largely because they fail to recognize his genius. He assaults his opponents by impugnation, questioning their honesty, intelligence, and motives.
#3 The Pseudo-scientist is paranoid and feels he is the victim of a vast conspiracy designed to suppress his brilliant work.