Because truths of different kinds exhibit the characteristics of incommensurability (their difference is such that they cannot be measured by a single standard or reduced to members of one series) and incompossibility (their difference is such that they cannot co-exist within the same system), such openness introduces both multiplicity and contradiction, and the creature in question stands divided against himself.

pp. 9-10 - Personal Destinies: A Philosophy of Ethical Individualism (1976)