That's where the word "generous" comes in! You can't go head to head in an office setting. What you CAN do however, is attempt to co-operate as much as you can, while doing your best to firmly maintain your boundaries.

As it says in the beginning, you can't negate the need for some form of strength. Whether its your leverage as a valuable employee / having alternative employment options / a boss's fear of the cost of replacing you should you quit / or whatever other form of a-symmetrical strength you have at your disposal - there's usually some form of bargaining power (strength) you can have.

If you truly have no cards, and your boss treats you miserably, you should be working to acquire some form of leverage, or leave the miserable bastard and pick your battles elsewhere!