inflexible
adj
(a) that cannot be bent or turned 不可弯曲的; 不能转变的
made of an inflexible plastic 用硬塑料制成.
(b) (fig 比喻) that cannot be changed, influenced, etc; unyielding 不可改变的; 不受影响的; 不屈的
an inflexible will, determination, purpose, etc 不可动摇的意志、 决心、 目的等
an inflexible attitude, rule, system 不可改变的态度、 规则、 制度.
Although mankind has undergone no general improvement in intelligence or morality, it has made extraordinary progress in the accumulation of knowledge.