Melissus of Samos (5th century BCE) was a Greek philosopher from the island of Samos near the modern-day coast of Turkey. He advocated the philosophical doctrine known as monism, suggesting that reality is single and unchanging. While very little is known about Melissus, he took part in a major battle in 441 BCE and penned one philosophical work called On Nature or On What Is, echoing the naturalistic and monistic stance that pervaded earlier philosophers' output. Due to his views, he is often considered a member of the so-called Eleatic school of Greek philosophy. As James Warren asserts, the fact that Parmenides’ ideas reached the opposite end of the Greek world underlines the circulation of ideas that pervaded the Mediterranean in that historical period.
The term Eleatic school of philosophy is used nowadays to refer to the thoughts of philosophers from modern-day Velia in southern Italy, namely Parmenides (l. c. 485 BCE) and Zeno of Elea (l. c. 465 BCE). They challenged a reliance on the senses as a path to truth, trusting logic instead. Parmenides wrote the poem On Nature, where he describes his visit to a goddess who shows him the Way of Truth and the Way of Opinion. The former is grounded in reality and is eternal, motionless, and changeless, while the latter ought to be avoided as it is based on the senses. Similarly, Zeno wrote several paradoxes, such as the well-known Achilles and the Tortoise, to prove that motion is impossible. The school exerted a significant influence on the thought of Athenian philosopher Plato (428/427 - 348/347 BCE) and his theory of forms, which distinguished between the world of the senses and the world of ideas, or forms.
At the time, Samos belonged to the symmachei (alliance), nowadays referred to as the Delian League, led by Athens in response to Persian invasions. According to Plutarch, Melissus was the son of Ithagenes, a philosopher in command on the island of Samos. Like Parmenides, Melissus was politically active and fought as an admiral against the Athenians in 441 BCE, which is the only reliable date we have for the Samian philosopher. When Athens declared war against the island, Melissus reportedly prompted his fellow islanders to counterattack, despite their relative inexperience and reduced number of ships. They won, seizing war supplies and gaining control of the sea. Eventually, however, Athens triumphed and overtook the island.
Eternity & Infinity
According to the 6th-century CE Neoplatonist philosopher Simplicius, Melissus composed only one work. As opposed to Parmenides, he wrote in an archaic yet clear, direct manner and in Ionic prose rather than in poetic form. This has led scholars to question whether Parmenides considered 'what is' everlasting or timeless. Melissus, on the other hand, clearly argued that 'what is' must have everlasting existence, since nothing can come out of nothing, as opposed to what our misleading perceptions may suggest. To support his views, he developed the following argument:
Whatever existed always existed and always will exist. For if it came into being, then necessarily before coming into being it was nothing. Now if it was nothing it will in no way have come to be anything from being nothing. (Fragment B1)
In a similar vein, while doubts persist regarding Parmenides’ approach to the size of 'what is', Melissus clearly suggests that it is spatially infinite in extent, from which he infers that there is only one. If there were more than one, there would be boundaries, so it is not enough for 'what is' to be boundless in at least one direction. It must be absolutely boundless. While in Parmenides, the limits and bonds underlined the stability and completeness of 'what is', preventing it from losing anything, in Melissus, it is the unlimited, or apeiron that prevents change.
Motion & Void
Melissus also argues against motion and the void. He states that what is empty is nothing and is thus 'what is not'. As a result, 'what is' cannot move and is therefore full, as it has nowhere to yield to. If we compare this to a bottle, for instance, it goes without saying that we can only fill it if it is empty. Similarly, we can only empty it if it is full. Melissus does not suggest, however, that it can be half full or half empty, since he considers the existence of only one thing, and it is either full or not full, he claims, since if it yields at all it is not full anymore. In doing so, Melissus underlines the impossibility of both internal change and motion per se, since if it is full it cannot move. In fact, he claims that density and rarity cannot exist in 'what is' and is, as a result, incorporeal:
It could not be dense and rare. For it is not possible that the rare should be full, like the dense: the rare thereby at once becomes emptier than the dense. (Fragment 7)
Melissus echoes Parmenides by objecting to a pluralistic view of reality essentially based on perception. He emphasises the inconsistency inherent in the changes between opposites such as hot and cold, hard and soft, and life and death. He also alludes to eternal forms and powers, which seemingly convey the omnipresence of change. Nothing is stronger than truth, he claims, and such superficial changes prevent us from seeing it correctly. He, therefore, believes that should plurality exist, each and everything must be like 'what is', which would, in his view, be inconsistent. In other words, on what grounds would one object be small and another one big? Why would one be soft and another one hard?
Reactions to Melissus
On some accounts, his thoughts eventually paved the way for the development of atomism in the 5th century BCE, advocated by Leucippus and Democritus. They would introduce a very small, indivisible, changeless, and eternal 'what is', the essence of all things, which they called 'atom', a term that would become the cornerstone of modern science. Others, however, suggest that Melissus' contention regarding the impossibility of void can be seen as a response to the atomists, rather than a precursor. Melissus is also mentioned in the Hippocratic On the Nature of the Human Being, in response to the apparently incoherent theories of natural philosophers who sought different first causes of the nature of things.
Despite the quality of his arguments, in De Generatione et Corruptione, Aristotle criticizes philosophers who defy the evidence provided by the senses. Aristotle attacks Melissus' defence of spatial infinity, which he considered based on faulty logic and a false premise. Melissus is also mentioned by Dante Alighieri (1265-1321) in his Divine Comedy as fulfilling the characteristics of what a philosopher should not be like. On the whole, however, the clarity of his arguments have shed a light on the nature of the Eleatic response to pluralistic views of existence, thereby playing an important role in the emergence of metaphysics and ontology.