I'm in the middle of reading a pretty solid book on the topic of advertising, management, and overall business approach: It's Not What You Sell, It's What You Stand For by Roy M. Spence, Jr. The key theme revolves around the extreme importance of the purpose and the success that stems from a clear and simple anchor that the purpose provides.
Nothing within the book is revolutionary - the reasons for having an important purpose are very compelling. So it's surprising to realize how few of the big and omnipresent companies actually seem to have a clearly defined, public-facing purpose. This is especially the case for larger and older corporations which now seem to only float on the sea of shareholder returns and net income growth.
I suspect that Lehman Brothers might have had a clear purpose at some point in time but that its anchor-less path of the last few decades led the company to the precipice of bankruptcy and dramatic death.