It seems that Heidegger’s goals are explaining the interconnectedness of everything, allow a place for God, give room for free will and to give us the incite he has had. He falls short, however, in giving strong arguments and along the way he gives up causality and rationality which some, perhaps, aren’t ready to accept.

Heidigger goes through ‘being a jug’ and comes to a list of characteristics;
“the twofold containing, the container, the void, and the outpouring as a donation… [this] gathering is the jugs presencing,”
These qualities, when ‘existing’ collectively, are what a jug is, this is ‘thinging’. He emphasizes gathering with reference to an old German word ‘thing’ which referrers specifically to ‘gathering’. He clearly wants to dissuade us from seeing this parallel as “accidents of an etymological game”. Instead he wishes to persuade us that ‘gathering’ is an integral part of the thing and world. While not explicit, he hints that since ‘gathering’ is integral, this form should be unsurprising when echoed in language.

The heart of Heidigger’s argument is the gathering of the ‘four’; earth, sky, divinities and mortals.
“The gift of outpouring is a gift because it stays earth and sky, divinities and mortals… It brings the four into the light of their mutual belonging.”
Heidegger gives no rationale for these categories; instead they are presented as obvious. Earth is everything physical except that of sky which is the heavens and stars. Humans constitute morality because “they are capable of death as death”. He seems to mean humans are conscious and when dead this is lost, whereas an animal’s death is simply earth becoming earth. Finally, divinities are "messengers of the godhead". Although not explained by Heidegger it seems akin to a belief that God's message is in all things and is wondrous. God either exists as these divinities divining (constituting God by ‘gathering’) or He is separate from our world.

Heidegger finally concludes that the world “presences by worlding”. “[The four] join together, worlding, the world”; since the four gather when the thing things it seems ‘worlding’ is all things ‘thinging’. However Heidegger says;
“the world’s worlding cannot be explained by anything else nor can it be fathomed through anything else. ... The human will to explain just does not reach to the simpleness of the simple onefold of worlding”
It seems that the world cannot be explained with the rules that govern it, such as causality. We must just accept that the world exists when things ‘thing’, but that there is no ‘reason’ (discernable to us) this. Perhaps he means to establish humans outside the world. But he gives no reason why we should refute reasoned argument, or how we should go about establishing things without the use of reason or other ‘laws’ of our world.

“The mirror-play of the world is the round dance of appropriating”, Heidegger seems to be using mirror imagery to explain how we don’t always (or perhaps never) see ‘thinging’ completely. We cannot see a jug containing and having a void simultaneously; and a jug is a jug whether we notice it ‘thinging’ or not. This leaves questions of how can we know something is ‘thinging’? It seems if it exists, it things; but how do we know it things? It exists of course! This argument is circular, however Heidegger would likely argue we do not need to know this and perhaps we ask too much of his theory.

Towards the end of his essay, Heidigger concludes that while “the jug is a thing insofar as it things” it “becomes a thing .. out of the ringing of the world’s mirror-play”. Things cannot exist outside the world. He also expresses that men are separated from the world and are not things; they can “attain to the world as world”. This gives room for free will, since if we’re not a part of the world we (like the world itself) are effected by causality.

If we accept Heidegger’s argument, that we can never understand the simpleness of oneness, how can we be sure of his proposal? It seems there are causal links between things and worlding. If this isn’t the case then it seems impossible that we have explained anything with Heidegger’s argument, we would have stated things but proved/explained nothing. However Heidegger would argue that the ‘ringing’ of ‘worlding’ is still affected by causality and it is this and not the world or ‘worlding’ that allows the existence of things.

Heidegger intends to use his poetry and symbolic imagery to indicate the simplicity of ‘worlding’ that we cannot comprehend, with intuition trying to explain intuition. At times it seems to obfuscate which disallows access to Heidegger’s insight. Heidegger’s explanation of mirror-play as ‘the round dance of appropriating’, leaves us to draw our own conclusion. The answer is not forthcoming. This leaves questions, like the place of language in Heidegger’s theory.

Heidegger’s argument is problematic partly due to his place for humans;
“…res means what concerns men… res designates that which concerns somebody, an affair, a contested matter, a case at law… The jug is a thing …[not] in the sense of res.”
However Heidegger takes the jugs’ characteristics (which allow for ‘thinging’) from the jug defined in language, adding a human element. Heidegger doesn’t address this (as good or bad), but it seems to make his argument less plausible; for if he wishes humans to be separate from the world it is hard to see how the world, as we have built, it is separate from us. How can our intuitions be unbiased since our own understanding of language has a part in the ‘thinging’ of things. But let’s assume the jug can have essential characteristics (perhaps due to a ‘purpose’). This only raises problem of the river; it is a river because we have defined characteristics that make a river. Without language to associate characteristics to a thing it is unclear how it could thing, so language is required for ‘thinging’. Heidegger’s theory could be modified, but only seeming less plausible as there is no independence of things.

In the end Heidegger’s argument seems fairly circular. For example,
“the jug is a thing insofar as it things”
“the gift of outpouring is a gift because it stays [the four]. …Staying … brings the four into the light of their mutual belonging.”
“This appropriating mirror-play of the simple onefold of [the four], we call the world.”
“becomes a thing .. out of the ringing of the world’s mirror-play”
It seems that a jug needs to thing and the ringing of mirror-play to exist. Yet the simple onefold requires the jugs ‘gift of outpouring’ to gather the four to allow for the mirror-play. Heidegger would argue that we cannot use causality to dispute his theory, since the world is not subject to the same causal/rational laws. If this is so then it’s unclear how we can validate Heidegger’s claims. Heidegger seems to want us to just accept the existence of things, the world, the four and their interconnectedness. So not only are Heidegger’s arguments circular, they are unfalsifiable which makes it less appealing.

Heidegger’s theory posits some arguments which fit well with our preconceptions. It makes sense that the universe may not be governed by the rules inside it. It’s plausible that things exists because they ‘thing’. However Heidegger’s theory seems to be based too much in intuition without anything to back it up. Things exist, it seems, because they exist. How does this help? He gives an account of free well, but it’s based on intuition only. He gives room for God but Heidegger never truly defines what he means by divinities, remaining open for attack. Perhaps the major problem, perhaps one Heidegger would agree with, was for all his poetry and argument some readers did/have not arrive at his insight. Though it’s likely Heidegger would claim we haven’t opened our minds enough to see the simplicity.
May I point out that the word count is 1200, you are allowed 10% over or under and this baby is exactly 1320 words.