What is the worst motivational memo ever written? Given that this is a wretched literary genre in which almost every example is lamentable, to find the very worst is a tall order.

Yet last week, the Financial Timespublished what seemed a sublimely bad memo written by a Royal Dutch Shell manager and asked readers if this could deserve the title.

The memo (www.ft.com/shell) is crass, poorly punctuated and most of it wasn't even written by its author, David Greer, deputy chief executive of Royal Dutch Shell's Sakhalin Energy Investment Company. He had lifted the words of General George S Patton with no attribution, and clumsily adapted them to spur on his team of recalcitrant pipeline engineers.

But does his memo really deserve to be named the worst ever? The verdict from visitors to FT.com is that yes it does, just.

I don't agree. Each time I look at it, I like it more. Not only is it not the worst motivational e-mail ever written, it is actually one of the better ones.

To prove my point, I'm comparing it with another leaked e-mail I received last week. This one was written by Jim Quigley, the new global chief executive of Deloitte, and dispatched to all staff on his first day in the new job.

In order to establish which of the two is worst, I've chosen four objective criteria. The first is clarity. On that score, the Shell memo does well.

"Lead me, follow me, or get out of my way," Greer says, which is not terribly hard to fathom.

The reason the language is so clear is doubtless the influence of Patton, who came from an age in which people still knew how to express themselves clearly.

Now consider the style of the Deloitte memo. "Our identity reinforces the shared vision of our member firms," it says. This is so profoundly meaningless that I doubt if its author could tell me what he meant by it.

The next criterion is that the boss must sound as if he is on the same planet as the people he is trying to motivate.

Again, high marks to Greer. He refers to "mutterings" and bad body language of staff at a recent meeting. In other words, he is aware that morale is bad and isn't frightened to discuss it.

Meanwhile, at Deloitte, the new chief is oozing platitudes as to the state of the company. "I have never been more proud of who we are . . . we strengthen our brand every day as we deliver value to our clients."

Next, a good motivational message must consider what it is that keeps employees in their jobs. Greer cites three reasons:

"To earn a decent living for yourself and your loved ones," self-respect and desire for success. This had me cheering (even though the phrase "loved ones" is not one of my favourites).

Most managers like to believe that workers are there for love of the company or, worse, for passion towards the brand. Money and other basics tend to get overlooked.

Over at Deloitte, matters are rather more intangible. "As our brand strengthens, the commitment we have to each other also increases," Quigley says, mysteriously.

The final standard for judging a motivational memo is by the tools it deploys.

In theory, managers can choose between stick and carrot, although most shun sticks through some misplaced fear that precious self-esteem will be damaged. Greer has no such inhibitions and sensibly uses both.

His carrot is a little flaccid, although arguably no more flaccid than most. "Pipeliners and engineers love to fight and win, traditionally," he says. I would beg to differ: pipeliners surely love to build pipes that are safe, durable, on time and on budget.

His sticks are better. "I despise cowards," he says, warning those who don't comply to "get out of my way". This is not terribly civil, but it makes him sound like a man who means it.

By contrast, here is another helping of mush from Deloitte.

"We will take our performance to the next level, provided we move forward collaboratively, as a team." Quigley doesn't sound as if he means it. He sounds as if he's had a partial lobotomy.

Though I admire the style of Greer, I still don't expect his exhortations will make any of his deviant engineers work harder.

This is because motivation is the hardest of all managerial tasks, and it is fanciful to expect any memo, no matter now well crafted, to make much difference. So wouldn't it be better to scrap them altogether?

No: because their true purpose isn't motivation. It is to remind staff that the boss is in charge, that he knows what he is doing and that he is attempting to improve things and is expecting a little help.

And so which of these two men is in control: the man who has adapted the uniform of General Patton, or the man who wraps himself in the obscurity of management talk with all its bland nonsense about celebrating, taking journeys together and "the powerful tapestry that is our brand"? There's no contest.

Does this then mean that Quigley's is the worst motivational e-mail ever?

Alas no. The saddest thing about his words is not that they are bad in the corporate scheme of things. They are simply average.