Dogmatic
Adjective
Characterized by or given to the expression of opinions very strongly or positively as if they were facts...
...arbitrary, arrogant, assertive, categorical, emphatic, fanatical, intolerant,
obstinate, stubborn, unequivocal, bigoted, bullheaded,
cocksure, confident, definite, despotic, determined, dictative,
doctrinaire, domineering, downright, egotistical, fascistic, formal, high and mighty, imperious, magisterial, narrow-minded, obdurate, one-sided, overbearing, peremptory, pigheaded,
prejudiced, stiff-necked, tenacious, tyrannical, wrong-headed...