Wikipedia has a lofty goal: a comprehensive collection of all of the knowledge in the world.
Indeed, the purpose of an encyclopedia is to collect knowledge disseminated around the globe; to set forth its general system to the men with whom we live, and transmit it to those who will come after us, so that the work of preceding centuries will not become useless to the centuries to come; and so that our offspring, becoming better instructed, will at the same time become more virtuous and happy, and that we should not die without having rendered a service to the human race.—Diderot
Wikipedia is intended to be the largest, most comprehensive, and most widely-available encyclopedia ever written:
Our goal with Wikipedia is to create a free encyclopedia; indeed, the largest encyclopedia in history, both in terms of breadth and in terms of depth. We also want Wikipedia to be a reliable resource.—Larry Sanger
Imagine a world in which every single person on the planet is given free access to the sum of all human knowledge. That's what we're doing.—Jimbo Wales