The Latin proverb "Ex Nihilo, Nihil Fit" means Nothing comes from Nothing. It is supposed to mean that you cannot expect results if you do nothing.
Parmenides came from Elea in the modern region of Campania, Italy, and lived far before the Romans. Parmenides was labelled the father of metaphysics and contrary to many ancient and classical philosophers, didn’t base his thoughts on observation but rather on pure reason. He can be considered the first armchair philosopher.
Metaphysics is the study of 'what is'. Parmenides set out two main concepts: Being (what is and must be) and Non Being (what isn’t, and can’t be). He articulated that one cannot talk about Non Being because it doesn’t exist. Following from this, he argued that everything is the same since if two things were different, one thing would NOT BE like the other. Since it is forbidden and absurd to talk about Non Being, the two things must be the same. In the end everything is one, and Being. And NonBeing is NonBeing.
Ex Nihilo, Nihil Fit could be playfully construed as an allusion to this Parmenedian tautology.
A very flamboyant personality, Empedocles supposedly died by jumping into a volcano! He believed that the cosmos was composed not just of the four elements earth, air, water and fire but also by love and strife. Love was responsible for bringing things together while strife pulls things apart.
The cosmos swings between states of dominance of love over strife and vice versa. When love is totally dominant, the whole cosmos is perfectly mixed with one another and takes the shape of a sphere. On the other hand, when strife ascends, the four elements are pulled apart and separate into their basic forms. Our universe with humans, planets, stars etc, can only occur in a state of conflict and balance between love and strife: when neither completely dominates.
Heraclitus (and Cratylus)
Often identified as the proponent of the idea that everything is in constant flux, Heraclitus' philosophy is actually more nuanced than that. He proposed the 'unity of opposites' idea spawning concise aphorisms such as: 'the road up is also the road down'. The relevant and perhaps his most famous aphorism is : 'You cannot step into the same river twice'. This is because the river is constantly changing and on your second step the river will be different.
One of his later followers Cratylus took this idea further and perhaps misinterpreted Heraclitus saying 'You cannot step into the same river once'. Cratylus presumably was saying that it is difficult to identify such a thing as the river in a static sense, since it is always changing. Hence you cannot step into it even once. This is perhaps an over extension as Heraclitus originally might have wanted to refer to his core idea of 'unity of opposites'. The river is both changing and the same, in this sense you can identify such a thing as the river, but at the same time it is also a different river as well.
Although Aristotle may be known as the student of Plato, the two philosophers shared several differences. One of such was their views on metaphysics. Whilst Plato viewed all beings to be derived from his Platonic forms, Aristotle viewed things as primary beings or the basis of concepts. In Aristotle’s mind, without any beings, there would be no such thing as large, square or beautiful because these ideas are derived from beings (rather than beings being derived from Platonic forms).
Each of Aristotle’s beings are the first things of predicate (with predicate being a property that a being can either possess or lack). The importance of being is further reinforced by the fact that substance (or being) is the first categories in Aristotle’s “The Categories”.
Moreover, in Aristotle’s book 2 of “The Physics”, we see him discuss the different causes for beings. The four causes were the efficient cause (what brings something about), the material cause (what something comprises), the formal cause (what gives something its form or definition) and finally, the final cause (the purpose or goal).
Aristotle believes nature to be teleological (where teleos in Greek means end or purpose). He argues that everything in nature involves a final causation. This could be argued to mirror Plato’s “demiurge” who constructed the world with purpose and design.
As well as his works on Metaphysics and Physics, Aristotle also wrote books about biology and zoology. In his "History of Animals", "Parts of Animals" and "Generation of Animals" he would write about the different attributes of animals, how they came into existence and other observations he had when viewing fauna life.