Ideas, styles, and motifs of the past may lose their appeal in a certain period or climate of opinion, but this must not be final, for they may regain their validity at another time and under different conditions. It is therefore important to preserve in libraries and museums the monuments of past thought and productive activity. They should always be studied by specialists, for antiquarian purposes, if you wish, but they may also regain their life and relevance, it were, at any time, and what was dead or unknown to one generation may suddenly and unexpectedly become important for the next.(1) Preservation is directed toward retention of the products of human for a conscious the library becoming an instrument of this activity. Human embraces not merely what the word culture conveys when used in its narrow sense, but rather refers potentially to the whole activity of human life and endeavor. Its Latin source, cultus, perhaps reveals this better than does our English derivative. Cultus is (1) the action of dwelling or inhabiting, (2) tilling the ground and raising animals, (3) training and education, (4) personal care and domestic maintenance. Among its other meanings are adornment, rhetorical elegance, standard or mode of living, worship, and pursuit of interest. Only late in the list comes something like our narrower sense of culture, the state of being refined.(2) Thus, the library's mission for the documentation of human covers a wide area, but one traditionally concerned with the document, whereas the museum has largely assumed responsibility for the artifact. This is an orientation pregnant with significance for preservation. The term today is, on the contrary, a much broader term than its ancient Latin source. No longer is it simply the written word; both categories have expanded. The means of writing may be by hand, press, photographic apparatus, electronic instruments, or a combination of these; and the thing recorded may be the word written or spoken, unspoken sound, or image. At times the document may even be what we more traditionally consider an artifact itself, thus breaking down the barrier of neat categories, at which point the library meets the museum. All this the library endeavors to preserve for even historically conscious posterity, for in that qualifier lies an implication of the human intellect coming to grips with, acting upon, becoming involved with, and struggling to interpret, understand, and communicate the data that constitute the record of its own activity, data that possess a latent significance. At the beginning of his history of the Peloponnesian wars, Thucydides outlines his method and states his purpose, expressing the hope that his work will become a ktema es aiei, an everlasting possession. It is a phrase unfortunate in its translation, and one that calls to mind a beautifully bound folio volume lying cherished in some protective corner while gathering dust through habitual disuse. Thucydides himself makes clear that this is precisely not what he means, it is not to be an anognisma es to parachrema, a trophy for the moment. He intends that it be ophelima, for as many wish to study clearly what has happened and will happen again sometime, is the way with the human condition.(3) In attempting this small work I am not so foolish, or megalomaniac, to compare it with Thucydides' history except in two respects: the desire that it prove useful, and the belief that human experience is to some degree common and thus valuable for and capable of communication. Implicit in both is an important philosophical premise that, though disputed in some corners today, is the foundation on which the purpose of preservation rests. Indeed, it is the foundation on which the concept of the library is erected. It is essential consciously to make that link between the practical and the philosophical, lest in future years we lose sight of our goal, its purpose, and its significance to human life. …