 Why does Macklin have objections to going back?
But Macklin is exactly what we need for a quick, dramatic test. "No, Harold, it isn't," Macklin admitted. "I would have said the common cold," Macklin replied, "but I suppose from what you have said you mean headaches." "Aspirins would still be used to reduce fever and relieve muscular pains," Mitchell said. Unless we can produce quick, conclusive and dramatic proof of our studies we can get no more financial backing. Ferris and I are confident that there is no danger.... By established periodic cycle he should be suffering hell right now, shouldn't he? "Mrs. Macklin," Mitchell said quickly, "I'm sure we can help if there is anything wrong with your husband.
 He doesn't want to go back. He'd rather be "stupid" than having headaches and always worrying.
 He doesn't want to have to undergo another experiment.  He doesn't want to go back. He'd rather be "stupid" than having headaches and always worrying.  It's too risky to try the experiment again. He'd rather take his chances the way he is now.  He doesn't want to go back. In the state he's in, he's too "stupid" to realize the ramifications of what happened to him.