I don't think it's any coincidence that the quotes I liked the best are from Thomas Jefferson and John F. Kennedy, nor that they still apply today.
On the Role of Libraries
Good libraries are as essential to an education and informed people as the school system itself. The library is not only the custodian of our cultural heritage but the key to progress and the advancement of knowledge. With increasing leisure its resources can enrich the quality of American life.
-John F. Kennedy, 1963
Books constitute capital. A library book lasts as long as a house, for hundreds of years. It is not, then, an article of mere consumption but fairly of capital, and often in the case of professional men, setting out in life, it is their only capital.
-Thomas Jefferson, 1821
On the Running of Libraries
Libraries like all other institutions must grow and adapt to changing requirements and conditions. The rate of change in the world today and in our knowledge of it is incredibly fast. We cannot afford to let our libraries slip behind.
-John F. Kennedy, 1963
Nothing would do more extensive good at small expense than the establishment of a small, circulating library in every county, to consist of a few well-chosen books, to be lent to the people of the county, under such regulations as would secure their safe return in due time.
-Thomas Jefferson, 1809
I found it interesting how different these two sets of quotes made these two Presidents sound. Kennedy's first quote is lofty and qualitative, describing the library's place in our society overall. And of course I like his second quote, laying out a general roadmap of continuous change for libraries, responding to the continuous change in our communities.
Jefferson's quotes are a little more grounded and quantitative, describing how libraries can help people - a library can help you get a job. And in the second quote, he describes the specific policies to run a library - which almost sounds like Jefferson would support DRM (except that libraries have been enforcing his suggestion for over a century without DRM).
Of course celebrating libraries during National Library Week is great, but I always have the tendency to look for mirrors to catch a reflection of how people outside the library world view libraries.