The Achilles of Rationalist Arguments is the first installment of the history of an argument pioneered by Ben Mijuskovic – most commonly designated the “Simplicity Argument.” This 1974 expanded publication of his doctoral dissertation provides the groundwork for this history and the inspiration for this website. The title is inspired by Immanuel Kant’s description of one particular philosophical defense which he challenges in The Critique of Pure Reason A351-352. His lofty consideration of a this defense used by rationalists illustrates its nearly “impenetrable” nature akin to the mythic hero Achilles.
Mijuskovic chronicles the history of this argument from Plato through Kant in this unique study. His contribution to the history of the simplicity argument is one of a systematizer. The argument has been utilized by the likes of Plato, Plotinus, Descartes, Leibniz, and the Cambridge Platonists. Mijuskovic specifically discusses the benefits of its use in three particular debates: personal immortality, the unity of consciousness, and personal identity.
The simplicity argument has a fundamental premise of the immateriality of thought. Thought being immaterial implies that the mind is a simple substance. Three conclusions can be made about the human mind from this initial observation of its simplicity (1) what is simple is indestructible, (2) what is simple is unified, (3) what is simple is an identity. These three prongs are fleshed out in subsequent chapters within The Achilles of Rationalist Arguments. This basic argument has been analyzed since Plato. Mijuskovic’s genius is in observing how it has been used throughout history. The Achilles of Rationalist Arguments primarily focuses upon the Cambridge Platonists, but it establishes a method for future consideration of others who have benefited from its use.
This heroic contribution emerged in a somewhat hostile environment of academic materialism. Fortunately, there seems to be a swelling interest in the 21st century regarding the simplicity of the soul and arguments pertaining to dualism in philosophy of mind. For this stance, Mijuskovic deserves much commendation.