What many people don't get is that cooperation is not the same as consensus.
Cooperation means someone takes the lead on an issue. If it makes sense, and if the leader is perceived to have good character and judgment, others follow. Otherwise, the project is stillborn. It's the way the market picks leaders. Not through org charts, but through action and response.
One person may be the leader on one issue and a cooperator on many others. Most people play both roles frequently.
Consensus, on the other hand, is the absence of leadership.