In the third section , the author discusses different functionalism types , including david lewis ' s commonsense functionalism , machine functionalism , homuncular functionalism and teleological functionalism . the author analyses two concepts , ramsey sentence and turing machine , which are important for functionalism , and explains the view of functionalism by using both concepts . in the fourth section , the author displays many difficulties functionalism faces 在第三部分，笔者论述了功能主义的分类，把其分为刘易斯的常识功能主义、机器功能主义、小人功能主义和目的论功能主义，重点说明了对功能主义影响深远的两个概念：拉姆齐语句和图灵机，通过这两个概念细致地说明了功能主义对心身问题的看法。
