Abraham Lincoln’s famous team of rivals were able to work together because they were just that, rivals—not enemies. Diversity of ideas and disagreement among your team members is healthy for your organization. All-out war is not.

In a recent blog post, Patrick Lencioni writes that when a team cannot productively engage in conflict the diversity can even become a competitive disadvantage.

Sometimes we all need to hear “no”.

Imagine the millions of dollars that might have been saved if more underlings had been bold enough to speak up when they recognized an idea as bad. Imagine the embarrassments and lawsuits companies could have been spared if someone had been willing to call out the flaws in a plan or concept.