Two Kinds of People - Knowers and Learners

I worked for a landscaper once who was doing things the same way he had learned them when he took a few classes in the '70's. Even if I would do a design that included new cultivars of shrubs, for example, he would substitute the old varieties he was familiar with. His trips to the horticultural trade show were mainly to find wholesalers who could still supply these old varieties. He took no hint from how increasingly difficult it was to get those shrubs that perhaps there were newer better alternatives. He knew how to do things and didn't see any reason to change that.

I was awed once to find I was volunteering next to an expert on prairie who was a locally renowned advocate of replacing lawn with prairie. She answered my questions but also asked me questions about my experiences with native plants. She was volunteering as she does every year on that project to gain more experience and see that patterns of how that particular prairie was changing over time. She know a great deal about prairie and is considered to be THE expert by many. Yet she also knows that she will never know everything and that new things are being discovered constantly and she continually wants to learn as much as she possibly can about her area of expertise. And she is willing to learn it from both other experts and also from anyone who has any experience or knowledge to offer.

Such experiences have lead me to the conclusion that there are two kinds of people: People who are certain they know and never seek to learn more, and people who aren't so certain of anything except that there is always more to learn and therefore want to learn more and grow and be challenged.

Which political candidate falls into which category?