SEMPLICE

Since indivisibility is unity («nihil enim est aliud unum quam ens indivisum»: St. Thomas, De verit., q. 1, a. 1, c.) and unity is convertible with being («Unum... convertitur cum ente»: ibid., De potentia, q. 9, a. 7), simplicity or indivisibility is a perfection or positive quality; but since human knowledge begins from the experience of the corporeal world, and the body is composite, the concept of simplicity is attained by negation of partibility or composition: it is therefore relative to that of the parts negated. Absolutely simple is that which has no parts whatsoever, that which is all and pure being, pure act: God (v.). Every finite being, even if spiritual, nonetheless entails a composition of act and potency (according to the summit of existence and essence). Spiritual reality, however, is relatively simple insofar as it has no quantitative parts; this simplicity proceeds, always in the Thomistic conception, from not having a composition of essential parts (matter and form): from being, that is, pure form. The body, composed of matter and form, is extended and as such is also composed of quantitative parts.