Perpetual

Perpetual (pronounced per-pech-oo-uhl)

(1) Continuing or enduring forever; lasting indefinitely; continuing or continued without intermission or interruption; ceaseless.

(2) In horticulture, blooming almost continuously throughout the season or the year; a perennial plant.

(3) As "perpetual motion machine", a hypothetical device which, which, once set in motion, will continue forever unless stopped by some external force.  Dating from the 1590s, however "constructed", it would violate either or both the first or second laws of thermodynamics and is thus a physical impossibility and now thought of as an engineer's version of alchemy.

1300–1350: From the late Middle English perpetual & perpetuall (everlasting, unceasing, existing indefinitely, continuing forever in future time), from the twelfth century Old French perpetual (without end; uninterrupted), from the Latin perpetuālis (universal ("permanent" in the Medieval Latin)), from perpetuus (continuous, universal), from perpetis, genitive of the Old Latin perpes (lasting; continual).  The construct of perpetu(us) was per (through), from the primitive Indo-European root per (forward (hence "through")) + pet (to fly, to rush), the root of petere (to seek; reach for; go towards; aim at) + -uus (the deverbal adjectival suffix (deverbal nouns are nouns derived from verbs or verb phrases, but that behave grammatically purely as nouns, not as verbs)).  The English forms were a direct borrowing from the Old French perpetual and the spellings perpetuall and perpetual co-existed in Middle English.

Synonyms include ceaseless, constant, perennial, unceasing, continuous, eternal, persistent, never-ending, incessant, unending, permanent, enduring, infinite, interminable, endless, recurring, continued, abiding, everlasting, immortal and uninterrupted.

Interesting points about Mary

The Roman Catholic Church’s dogma of papal infallibility holds that a pope’s rulings on matters of faith and doctrine are infallibility correct and cannot be questioned.  When making such statements, a pope is said to be speaking ex cathedra (literally “from the chair”).  Although ex cathedra pronouncements had been issued since medieval times, as a point of canon law, the doctrine was codified first at the First Ecumenical Council of the Vatican (Vatican I; 1869–1870) in the document Pastor aeternus (shepherd forever).

Since Vatican I, the only ex cathedra decree has been Munificentissimus Deus (The most bountiful God), issued by Pius XII (1876–1958; pope 1939-1958) in 1950, in which was declared the dogma of the Assumption; that the Virgin Mary "having completed the course of her earthly life, was assumed body and soul into heavenly glory".  Pius XII never made explicit whether the assumption preceded or followed earthly death, a point no pope has since discussed although it does seem of some theological significance.

Prior to the solemn definition of 1870, there had been decrees issued ex cathedra.  In Ineffabilis Deus (Ineffable God (1854)), Pius IX (1792–1878; pope 1846-1878) defined the dogma of the Immaculate Conception of the Blessed Virgin Mary, an important point because of the theological necessity of Christ being born free of sin, a notion built upon by later theologians as the perpetual virginity of Mary.  It asserts that Mary "always a virgin, before, during and after the birth of Jesus Christ", explaining the biblical references to brothers of Jesus either as children of Joseph from a previous marriage, cousins of Jesus, or just folk closely associated with the Holy Family.

Wall painting (unknown artist), circa 1870, in Saint Laurentius Church in Voorschoten, the Netherlands, painted to commemorate Pastor aeternus.  It depicts Saint Thomas Aquinas (1225-1274) holding his book Summa Theologica (1265-1274), Jesus Christ (with the Vatican in the background which was a nice touch) and Pope Pius IX.