Thank you for your very interesting Plotinus quotation and Nagarjuna-related question.
The tetralemma of the Indian Buddhist monk Nagarjuna states:
1) All exists.
2) All does not exist.
3) All exists and does not exist.
4) All neither exists or does not exist.
This is how Nagarjuna (the 14th Ch’an Patriarch) summarises the entirety of the Buddha’s teaching. Therefore, we may state that:
a) The mind exists.
b) The mind does not exist.
c) The mind both exists and does not exist.
d) The mind neither exists nor does not exist.
This may be viewed as a developmental schematic of ever deepening understanding or awareness of the mind-body nexus and its essence. Exactly the same analysis can be applied to ‘matter’ but not to ‘spirit’ – as the Buddha rejected the notion of a spirit or mind that exists in opposition (or ‘outside’ of) the material world. In the Theravada School the mind-body nexus is ‘empty’ of ‘atma’ (or ‘soul’), but appears to contain a personal self (i.e. perceiving ‘mind’ function) that is a temporary coming together of elements which dissipate at death. In this school the physical world ‘exists’, but is ‘empty’ of any permanent state. In the Mahayana and Vajrayana Schools – the idea of ‘emptiness’ is exactly the same – but is extended so as to imply (or suggest) that the world of physical matter is ‘empty’ of any and all substantiality. However, as the Buddha also rejected any notions of ‘eternalism’ and ‘nihilism’ – these schools must be careful in their analysis. Therefore, we can say:
i) The world of matter exists.
ii) The world of matter does not exist.
iii) The world of matter both exists and does not exist.
iv) The world of matter neither exists nor does not exist.
Perhaps the 4th statement is the enlightened position, and although the world of matter may not exist as we think it does – it is also true from a Buddhist perspective – that the world of matter does not exist as we may presume it not to. This is not merely a matter of semantics – but a matter of actual inner and outer realisation attained through self-cultivation, experience and assessment. In the Four Noble Truths the Buddha clearly states that material existence is the basis of physical life and all subsequent philosophical development. This suggests that existence and the world of physical matter are inherently linked, integrated and entwined. In other words, the Buddha appears to be stating that a non-embodied existence is impossible, as the basis for life. In this regard, he is in agreement with the Greek philosopher Epicurus (with life being a special arrangement of atoms that congeal at conception, and fall apart at physical death). This view would correlate with the Buddha’s five aggregates – although the Buddha does seem to entertain a ‘limited’ notion of rebirth (not evident in the five aggregates themselves) which is negated at the point of the realisation of enlightenment.
As for Plotinus, it is important to consider that his original Greek thought has been translated into Western languages usually involving an underlying Judeo-Christian influence that attempts to separate his teaching into a ‘rejected’ material world and an ‘accepted’ spiritual world (that stands in opposition to the material world). One prime example of this modern Eurocentric bias is the continuous rendering of the Greek ‘psyche’ (i.e. ‘breath of life’) as the Judeo-Christian ‘soul’ which implies a completely different meaning. The Greek ‘pyscho’ refers to the spark of life in the functioning conscious mind that defines human existence – whilst the Judeo-Christian ‘soul’ is a completely different entity that links a monotheistic entity to each individual person. A ‘soul’ may be related to an individual’s mind and body – but remains continuously ‘distinct’ from both the mind and body, so that at the point of physical death, the ‘soul’ survives and moves into another dimension of existence (leaving the mind and body behind). The confusion arises from the fact that the early Christian ideologues took the Greek term ‘psyche’ and changed its definition and usage (rejecting the original Greek meaning). Later, when Christianity spread into pagan Germany, the non-Christian Germans believed in a pagan entity called a ‘soul’ which the Christian missionaries could not prevent. Their answer was to usurp this non-Christian term and use it in a Christian manner, therefore, a distorted interpretation of the Christianised Greek ‘psyche’ became commonly known as ‘soul’ within Christian theology. As I said above, the Christianised ‘soul’ concept has no bearing whatsoever upon the philosophy developed by non-Christian Greeks! I think this is important because the term ‘matter’ is often viewed within non-Christianised Greek philosophy – a priori from a Christian position. Obviously, this is incorrect and constitutes a ‘category error’. Plotinus does use various words referring to ‘divine’ or ‘god-like’ states of mind – but despite seeking a realisation of ‘Oneness’ – the schematic of Plotinus has nothing to do with monotheism. From correctly translating from the Greek, it would appear that Plotinus is advocating an ever rarefied perception of the essential nature of material existence – with lesser understanding in the material world serving to ‘corrupt’ matter. This may be taken to imply that the deep insight that Plotinus found (and according to him – all people possess) is ‘hidden’ by an obscuring layer of ‘not understanding’ material existence in its highest frequency. Perhaps today, this might correspond to human awareness (or ‘consciousness’) at its highest degree of development, being associated with light energy, and ignorance as being trapped in congealed light energy, (i.e. light energy slowed down), which constitutes material existence.
PS: Curiously, as far as I am aware, the Pali term ‘atma’ also means ‘breath of life’ – like the Greek term ‘psyche’. For religionists, this ‘breath’ or ‘spark’ is divine, whilst for materialists, this term is natural in origin.