All Freeman's biographers recognize the huge influence Dr. Keen had on his life and career, and Jack El-Hai persuasively suggests that it's from such incidents as the ones in today's comic that teenage Walter learned how a famous doctor deals with the press. Dr. Keen put up with crazy bullshit like a newspaper's claiming he could resurrect the dead (complete with a fake interview with the dead man!) because through articles and letters to the editor he used the papers to make his case for medical stuff like why vivisection was awesome. It's a straight line from "Dr. Keen cures death" to "Lobotomy cuts the worry nerves of the brain." (The former is not a direct quote but I believe the latter is.)
What people tend to skip over is whatever influence Dr. Keen's daughter Dora may have had on her nephew's youthful sensibilities. Like her father she did things no one had done before, only in her case it was climbing mountains no one had climbed and making camp in a cave with nothing but candles for fuel. Like her father she loved a challenge and she loved writing about a challenge -- for outdoorsy magazines in her case. And what was the thing Walter loved doing most, after assaulting people's orbitals? Hiking, just like Aunt Dora. It wasn't just medicine that was a family tradition: it was bold exploration of the unknown, and then writing about it -- and having people read what you wrote, because you were famous. I think Dora might have made a big impression on Walter.
So here's William Williams Keen, totally ready to stand on that box and break into your skull, and here's a picture of Dora Keen in action one hundred years ago. And here's one of the many things Dr. Keen wrote. The title, I Believe in God and in Evolution, is a good example of what substitute calls an "implied dammit."
One thing Walter seems not to have inherited from his grandfather was a tender heart. He writes of Dr. Keen that for the forty years that he outlived his wife, he could barely speak of her without crying. Every year on the anniversary of her death he would lock himself in his room to be alone with his grief. He was also a devout Baptist who believed that the neatly compartmentalized brain areas were proof of God's handiwork, which means that for him brain surgery was a kind of worship, a constant replenishment of his faith. I think it's safe to say that Walter did not feel the same.