> Physical labor is great for the mind, as it leaves all kinds of time to consider the world.

Really depends on what kind of labor is it, not all of it is equal. I've had a new doors installed in my apartment yesterday, and the amount of troubleshooting and stress that the installers went through is not smaller than what I've faced in my programming job. But, I didn't have to do it while sweating from lifting 100 kg doors onto fourth floor, and later repeatedly trying to wrangle them into place.