The doctrine of the clarity of Scripture is a Protestant Christian position teaching that "...those things which are necessary to be known, believed, and observed, for salvation, are so clearly propounded and opened in some place of Scripture or other, that not only the learned, but the unlearned, in a due use of the ordinary means, may attain unto a sufficient understanding of them". Clarity of scripture is an important doctrinal and Biblical interpretive principle for historical Protestants and, today, for many evangelical Christians; it is adhered to by the Lutheran, Reformed, Anglican and Methodist churches. Perspicuity of scripture does not imply that people will receive it for what it is, as many adherents to the doctrine of perspicuity of scripture accept the Calvinist teaching that man is depraved and needs the illumination of the Holy Spirit in order to see the meaning for what it is. Martin Luther advocated the clearness of scripture in his work On the Bondage of the Will. Arminius argued for the perspicuity of scripture by name in "The Perspicuity of the Scriptures".