(FORTUNE Magazine) – This is my last Brave New Work column. It's over. Why? Creative differences. A mutual decision. I'll be leaving to pursue personal interests, explore other opportunities, etc.

But seriously, the thrust of the Careers section has changed, and what this column tries to do becomes less relevant. What color is my parachute?

Please consider this a sort of exit interview. Before BNW leaves the premises--or is forcibly removed--it has a few valedictory remarks. These reflect the more painful lessons learned over its past three years of employment. Why pick the painful ones? Because the truth hurts.

"The human brain is not an organ of thinking but an organ of survival, like claw and fangs," observed Albert Szent-Gyorgyi, the Nobel laureate biochemist. "It is made in such a way as to make us accept as truth that which is only advantage."

Works for me. When you write about the future of the workplace, you quickly appreciate that rationality is wildly overrated. Survival is not. Managers preach cognition but practice emotion. I've never been in a workplace where the majority of people believed that important decisions were made for primarily rational reasons. It's affected every column I've written.

So when I began Brave New Work, I half-joked that every column must pass two tests: It had to appeal to at least one of the seven deadly sins, and a consulting firm should be able to build a practice based on the core concept. The visceral married to the usable. BNW was designed to use innovation as an excuse to examine human behavior, and vice versa.

After all, workplace innovation is as important to success as marketplace innovation. The Innovator's Dilemma haunts HR as ghoulishly as it haunts HP. The challenge will always be how innovation--whether technical, organizational, cultural, or political--can be profitably adopted and adapted by a firm.

But there was absolutely no way that challenge could be--or would be--met by coolly rational analysis. In an era when intranets and best practices and 360-degree reviews and mobile computing were weaving themselves into the infrastructure, it seemed obvious that interpersonal dynamics would trump formal planning. Managers misbehave. People cheat. Executives game the system.

That's the Iron Law of Perverse Consequences. No organization can confidently know how its people will react to a new idea. Even the best-planned innovations can prove shockingly counterproductive. One marvels at the Wile E. Coyote-ness of it all. The FORTUNE 500 does shop at ACME. Beep-beep.

In retrospect, if there's a single common strand in the columns, it's the workplace--factory floor or white-collar cubicle--as a medium for constant experimentation. Sometimes the worker is the unit of experiment, sometimes it's the team; sometimes the technology shapes the hypothesis. The issue is never change for the sake of change, but change--whether radical, fundamental, or incremental--as a tool. Yes, change is a means to an end. But the end itself is constantly, chaotically changing in unpredictable ways. We're reduced (or elevated?) to constantly experimenting with how we experiment. We're simultaneously scientists and subjects.

My dispassionate view is that the Brave New Workplace is evolving into high-tech laboratories cum petting zoos where clever animals regularly vivisect themselves and their relationships with the latest cutting-edge tools. Does that sound too harsh? Perhaps.

But I confess to being taken aback by my past columns. I'm neither sympathetic nor nice. I'm not shocked when people behave badly. I expect it. I'm impatient with those who believe organizations should be designed to bring out the best in people when in fact I think we do well if we can prevent them from bringing out the worst.

The author of those columns isn't a kind person, but workplaces are not kind environments. Nor should they be. But the absence of kindness should never be confused with the absence of integrity. If there's a single issue that frightens me about the workplace future, it's the rising willingness of people to blame institutional imperatives for betraying their own values. Managers are not corporate Eichmanns merely following executive orders. Then again, it's become increasingly difficult to find managers ready, willing, and able to resign on principle. That willingness and ability will be the single most important metric to assess the emotional and cultural health of the workplace. There's no shortage of talent and intelligence; character may be the scarcer and more valuable commodity. That's the one to watch. That's the one that ultimately determines the economic and human value of innovation.

Our passion for productivity increasingly depends upon the productivity of our passions. We can't divorce commitment and caring from efficiency and effectiveness. We're constantly negotiating the tradeoffs within these matrices of conflicting values. That's why so many people find relationships in business every bit as thrilling, alluring, and, indeed, satisfying as the relationships in their personal lives. Is that healthy? I haven't a clue.

Brave New Work isn't about grand visions or leaping into tomorrow; it's about having the courage to take chances and the integrity to learn from the results. That's what I passionately care about. I'm grateful that I had the opportunity to explore it on these pages. I'm honored that so many readers have taken the time to share their thoughts. I'm sorry it's over.

Feedback? careers@fortunemail.com

Michael Schrage is co-director of MIT Media Lab's e-markets initiative and the author of Serious Play. He can be reached at michael_schrage@fortunemail.com.