Freedom of thought and freedom of expression are essential in the pursuit of reason.

CENTERFORSECURITYPOLICY: From fashion to fortitude: the road to resilience

For this reason, it is essential that the outside world puts pressure on Mr dos Santos.

ECONOMIST: This is Angola's best chance for peace for a decade

For this reason, it is essential to understand local impacts and to build adaptation planning and action around community-level concerns, priorities and aspirations.

UNESCO: Communication and Information

It is for this reason that The Signal and the Noise is essential reading in the era of Big Data that touches every business, every sports event, and every policymaker.

FORBES: A Guide to Thinking In the Era of Big Data: Nate Silver's "The Signal & The Noise"

And the single biggest reason why so many companies eventually lose that essential spark of innovative passion as they grow is a failure to institutionalize--through mission, culture and methodology--these critical ingredients.

FORBES: Is Google Simply Wasting Its Money?

One reason that certain foods carry so much local meaning is that they capture something essential about a region's flora and fauna.

WSJ: NattO, Maggot Cheese and Other Food That May Repel

One reason why the Cypriot bailout debacle matters - perhaps the main reason - is that it shows how far the eurozone is from the kind of solidarity which many believe essential to the currency union's long-term survival.

BBC: Cyprus and the eurozone's survival