Dear Mr. Gates:

Your article in the May 15 issue of Time magazine, "The Case for Microsoft (MSFT)," is important and needed. You should write more. There are many who want to understand the principle that has led you to fight this case. They will understand it only from you. Your lawyers are excellent, your spokesmen passionate. But only you can talk about principle.

For this is the part of the case the commentators don't get. They are baffled that businessmen don't settle. But this is clearly more than business for you. You are fighting for a principle, and you should be respected for that.

At times, you have said that this principle is the right to innovate -- the right of Microsoft to build innovative new technologies. You point to the last 25 years and to the explosion in personal computing produced in part by Microsoft's innovation. You defend that past and its promise for the future.

In this, you certainly are right. There can be no doubt that Microsoft has produced extraordinary innovation. You have created a platform upon which others can build; millions have built upon it. This is not an accident; it reflects good design. It is a measure of the excellence that Microsoft has made common.

But the question before Judge Jackson is not Microsoft's effect on innovation in general. The question is much more narrow. No one claims you have chilled all kinds of innovation. The charge is that you have chilled innovation of a certain type - that while you have encouraged and supported the innovation that has made your operating system more valuable to consumers, you have attacked and undermined innovations that might make the power of your OS less secure. The complaint is that you have tilted the platform to defend it against products that might threaten its dominance.

That's the nub of the government's case. The law does not require you turn and run when a new competitor walks onto the field. But it does police how a dominant firm responds. The law's aim is to preserve consumer choice in this competition, to trust consumers to choose the better of the products, and to encourage companies to compete for that choice.

But when a sufficiently powerful competitor interferes with the process of choice - by forcing others to narrow consumers' options, or by biasing the platform against competitive products - I had thought it clear that the law had a reason to respond. I had thought it obvious that the law should preserve the sovereignty of consumer choice.

You seem to think differently. You seem to believe that the right to innovate means the right to both produce more attractive products, and the right to undermine consumers' ability to choose products they might find more attractive than yours.

For example, the government uncovered an e-mail from you to your software developers that directed them to change the nature of Outlook so your handheld systems would run better than competing products using Outlook could.