In the following passage, some of the words have been left out. Read the passage carefully and select the correct answer for the given blank out of the four alternatives.

The written word is necessarily confined _________ the things of the understanding because only the  understanding has written language; whereas art deals ___________  ideas of a different mental texture, which words can only vaguely ____________. However, there are a large number of people who, _____________ they cannot be said to have experienced in a full sense any works of art, have undoubtedly the impelling desire which a little direction may lead on to a fuller ____________. And it is to such that books on art are useful.