Although
he is considered the founder of Neoplatonism, Plotinus would neither have thought
of himself as the founder of a new school of thought nor as holding a "new"
Platonic philosophy. Instead, he believed that he was simply continuing in the
Greek philosophical tradition of redefining the teachings of Plato. While almost
all schools of thought during Plotinus's time, especially the Christians and
the Gnostics, were incorporating Platonism into their ideology, he was the first
philosopher to formulate Platonic theory into an intellectual answer to the
question of personal salvation (Moore 2). For Plotinus the purification of the
soul was reached through a love and pursuit of wisdom (i.e. - philosophy) that
culminates in a mystical union with True Reality (Wallis 3). This is not to
say, however, that Plotinus borrowed nothing from other philosophies as well.
In fact, the early threads of Neoplatonism were most likely a result of the
cosmology in Timaeus and the creation chronicle of Genesis (Moore 1).
Since Plotinus is the "founder" of Neoplatonism, an in-depth analysis of his philosophy is reserved for the section, Reality; but it is important to note here that Plotinus was unique because his philosophy was a form of mysticism. In other words, he taught the necessity of direct experience and contemplation of Ultimate Reality, otherwise known as "The One." In this mystical experience, the mind is perfectly unified with the ultimate level of reality and individual limitations are abolished. Along with this, conceptual thought and sense imagery are transcended by obtaining a vision of the perfect unity of being. For this brief synopsis, however, the critical element to understanding Plotinus is that the purification and salvation of the individual soul is accomplished through philosophy (Wallis 3). The unique aspect of Neoplatonism, then, is that it was a philosophy that offered an intellectual path for the salvation of the soul. Clearly, Plotinus's ideas were partly a result of an era filled with insecurity concerning the eternal destiny of one's soul as evident by the proliferation of savior cults and religions that held to revelations claiming the need for salvation (Wallis 7).
Plotinus's method of teaching is also of interest here because it corresponds
with his philosophical beliefs. Following the Platonic tradition, he rejected
any styles that were ridged and formal preferring instead to spend days answering
his pupils' questions. His teaching, as well as his philosophy, was focused
on how a man goes from the existential reality of everyday life to contemplation
of The One; and he often used stories of his mystical experiences along with
vivid imagery (1) to conclude his teachings (Wallis 42).
Porphyry
Porphyry of Tyre was the principle student and biographer of Plotinus; however, his philosophy differed greatly from his teacher's because he believed that Plotinus's teachings were too difficult for the average man to comprehend (Wallis 3). Obviously, Porphyry was concerned with the practical aspect of salvation; and this led him to formulate a theory in which the soul could effectively transcend to higher levels of existence, namely the Intellect, through virtuous good works. One may note that this doctrine bears some similarities to the Christian idea of justification through works. It is quite possible, as stated by the historian Socrates and St. Augustine, that Porphyry had once been a Christian (Moore 6). If this is true, then it would explain "his belief in the soul's objective relation to the divine Mind - an idea shared by Origen, whom Porphyry knew as a youth" (Moore 7) as well as his conception of perfection being reached as part of a gradual process in contrast to the "instant salvation" that Plotinus favored.
Along with this, Porphyry believed in the existence of a universal means for the soul's liberation. This was in contrast to Plotinus who held that Truth could not be perceived through external reality and was thus only knowable to those enlightened by It. Because he was unwilling to accept Plotinus's insistence upon mystical salvation, Porphyry looked towards the practice of astrology as a universally accessible method of directing the soul on the proper path to liberation (Moore 9).
Iamblichus
Iamblichus of Apamea, following the standard progression of Greek philosophers, was instructed by Porphyry. Regardless of this, he departed significantly from the standard Neoplatonic thought formulated by Plotinus. Most notably, he conceptualized a Supreme One over and above the One of Plotinus. Iamblichus's One generated the intelligible cosmos and yet was wholly unknowable and inexpressible by the human intellect (Moore 7). This was opposed to Plotinus who believed that Supreme Truth is finally and necessarily expressible into language (Moore 9). Iamblichus also divided the single nature of the Soul into three parts: the cosmic, rational, and irrational soul. Finally, because he placed the One at such a distant level from conceptual reality, Iamblichus theorized the existence of intermediate spirits between the lower realms of the soul and the intelligible cosmos. These creatures, similar to daemons, provided a conduit through which human beings could perceive higher levels of reality. This led him to promote the use of proper ritual, known as theurgy, in order to compel the gods to purify men's souls and thus allowing them to gain knowledge of the higher realms (Moore 7). Therefore, for Iamblichus "the relation of humankind to the divine is one of subordinate to superior" (Moore 7).
1. For examples of Plotinus's use of imagery in his description of mystical experiences, please see Plotinus, The Enneads, VI. 4. 7.