In a moment that marks the maturing of an industry long intoxicated by its own momentum, Microsoft has chosen to place voluntary limits on how far and how fast it will push the boundaries of artificial intelligence. CEO Satya Nadella's internal warning to employees about the risks of losing control over advanced systems reflects a growing recognition that the capacity to build something does not, by itself, constitute a reason to build it. The company's new code of conduct is less a technical document than a philosophical one — an acknowledgment that power, left ungoverned, tends to outrun wis