Freedom of Information Day is celebrated on the birth anniversary (in 1751) of James Madison, our young nation's fourth president. Madison is remembered as the Father of the Constitution and as the man who cautioned "the advancement and diffusion of knowledge is the only guardian of true liberty;" and who believed "there are more instances of abridgement of freedom of the people by gradual and silent encroachments by those in power than by violent and sudden usurpations." (来源：www.EnglishCN.com)

More than two centuries after Madison's birth, his passion for a free and open government—and access to information—lives on in such legislation as The Freedom of Information Act and the various Sunshine Laws.

We're marking the day with a look at the somewhat uncommon (but hardly hidden) synonym of openness and unobstructedness: patency.

Patency comes from patent, of course, an adjective whose linguistic ancestor meant "to be open; exposed; be evident." Two now archaic meanings of patent were "available for public use;" and "accessible; exposed;" to this day, patent still enjoys its original sense, "open to public inspection." This sense is familiar to us in the phrase letters patent, which helped develop the sense of patent of interest to inventors and others seeking to protect their work.