Both theorists were able to put forth ideas that have great validity in the understanding the adult learner. I tend to give a slight nod to Dewey over Rogers. I think that Dewey was more focused on constructing a vision of education that embraced all learners and has particular applicability to the adult learner. Certainly, Rogers advocated many ideas that have direct applicability to the adult learner. The ideas of ensuring trust within the learning setting and constructing content with a "person- centered" approach are essential to better understanding the adult learner.
Yet, I think that Dewey's notion of instrumentalism already embraces this. Dewey understood that metaphysical articulation of absolutes is secondary to experience and grasping the understanding that different approaches to problem solving is where true learning happens. Dewey's commitment to the social experiment of democracy for all learners is something that makes his theories more applicable to the adult learner, understanding that the adult learner can articulate experiences others cannot. Dewey's work in the field of education was one in which all of his efforts sought to enhance the learning process of all learners, including adult learners. Rogers was more focused in clinical psychological, with applications in education. Given the nuanced condition of the adult learner, I think that Dewey was in a better position to understand the adult learner given his complete immersion in education for all learners, including the adult learner.