In other words, he wants to hire folks who can track all the minutiae involved in testing and also come up with new and unexpected ways to test the product. Others have told me they look for people who are naturally curious, who like to explore. Still others have said they look for people who are naturally destructive, but in a constructive kind of way. I hired him. When I interview testers, I try to find out as much about how they think as what they know.
Testing is problem solving.
Developing a good series of tests requires an ability to think through multiple possible paths to determine the important combinations. Tracking down bugs requires an ability to troubleshoot effectively, to eliminate unrelated variables, to reduce the problem to the simplest case. As a result, a good tester is both logical and intuitive. Other attributes are required too. Testers need to be detail-oriented.