Abstract
Using six decades of researches unknown to Perry, I here aim to survey carefully the various factors affecting the personal temperaments of William James and Josiah Royce. Such a survey creates a background against which later one can better examine their philosophical interactions. Initially, a comparison-contrast of their temperaments symbolizes James as an "eye" and Royce as an "ear". Then a more detailed study explores their differences in age and health, personal gifts, the "significant others" in their lives, educational opportunities, and their religious upbringing and attitudes. These factors significantly illumine the decades-long philosophical interaction of these two American philosophers