When allegations surfaced last month that Facebook routinely suppressed conservative points of view in its Trending Topics news section, the company worked aggressively to convince the public that it wasn’t intentionally tilting to the left of the political spectrum.

Mark Zuckerberg, the company’s co-founder and chief executive, invited conservative luminaries to Facebook’s Silicon Valley headquarters, and over some fancy snacks, they seemed to make peace. The issue blew over. Yet it also seemed to raise deeper questions about Facebook’s power to influence how we understand what’s going on in the world.

Measured by web traffic, ad revenue and influence over the way the rest of the media makes money, Facebook has grown into the most powerful force in the news industry. But the social network has never quite labeled itself as something analogous to a news organization, and it has been both uncomfortable with and unprepared to answer questions about whether it strives to adhere to journalistic ethics.

Should we be thinking of Facebook as a news site? Is that how Facebook thinks of itself?

No, not primarily, Facebook now says. In a document posted on Wednesday, the company explained, for the first time, the “values” that govern its news feed, the scrolling list of posts that Facebook presents to its 1.65 billion users every time they log on.