Leading article: The brain needs quality time

So much information; so little time to absorb it. It's the lament of the age and was the gist of Barack Obama's overheard advice to David Cameron at the weekend, inadvertently picked up by an ABC News microphone.

The senator confided that "should we be successful, that actually the most important thing you need to do is have big chunks of time during the day when all you're doing is thinking." Without that, "you lose the big picture".

Many great leaders would agree on the folly of letting "guys chalk your diary up," as Mr Cameron replied. Sir Winston Churchill for one never succumbed to this pressure. Had he done so, he would surely never have found the time to commence his monumental History of the English Speaking Peoples while in opposition in the 1930s.

But perhaps a more interesting voice in this context is that of Hanna Arendt, the German-Jewish philosopher who coined the now famous phrase about "the banality of evil". She held that creating what she called "thinking space" was not an indulgence, or even a form of relaxation; it was the hallmark of a healthy society.

"Thinking is possible among people who know how to talk back and forth with one another," she noted. "That's how one learns to think." Next time Mr Cameron feels under pressure to justify his time spent in Opposition with a mass of policy statements, he may like to borrow Arendt's words in defence of his right to be still thinking about them. "Thinking will atrophy in an environment that lacks the stillness that allows us to concentrate in inner dialogue," he could say. Let's see Government spin doctors respond to that.