(Bertrand Russell, A History of Western Philosophy, 1945.)
Philosophy, as I shall understand the word, is something intermediate between theology and science. Like theology, it consists of speculations on matters as to which definite knowledge has, so far, been unascertainable; but like science, it appeals to human reason rather than to authority, whether that of tradition or that of revelation. All definite knowledge—so I should contend—belongs to science; all dogma as to what surpasses definite knowledge belongs to theology. But between theology and science there is a No Man's Land, exposed to attack from both sides; this No Man's Land is philosophy.
所謂的哲學，就我的想法而言，是一門介於神學和科學之間的學問。有如神學，它所探討的主題，是明確知識目前尚不可及的問題；但有如科學，它訴諸於人類理性，而非源自於傳統風俗或信仰啟示的權威。所有的明確知識—我認為—都屬於科學；而任何主張某些事物超越了明確知識可及範圍的獨斷教條，則都屬於神學。但介於神學和科學之間，卻存在著一片無人地帶，暴露在來自這兩門學問的攻擊之中；這片無人地帶就是哲學。
