There is a strong penchant towards attributing observed enigmas to Haki. I intend point out key points in order to give a cogent answer by relying on the linguistics to extrapolate what we’re observing when Zoro cuts steel for the first time.
Zoro is faced with a colossal challenge. A new foe against whom his every swing, though powerful, is made redundant by the passive nature of his steely body. It doesn’t take long before he’s on the receiving end and we see Zoro buried under a pile of rubble.
Not only is his confidence buried, but his Swordsmanship has just hit a wall . He questions his swordsmanship; he trains harder than anyone; more dedicated than anyone and strives higher than anyone. These are surely recipes for success, but still, Zoro has realised he’s lacking something.
…Master Fails to Cut Paper but Talks of Cutting Steel??
Zoro buried in rubble and almost being lulled into unconsciousness reconnects with a distant memory where he ecstatically requests the truth as to whether there are Swordsmen capable of cutting steel.
This scene holds so much significance. What we see here is pretty outstanding. On the surface, it seems like a blunder, and an embarrassing one at that. Zoro tells his master of men that can cut steel, and his master demonstrates this by attempting to cut paper; the paper is still intact.
How is failure to cut paper in any way relating to cutting steel? In reality, his mentor was actually letting him in on to the answer and goal he strove towards.
A Blade that Cuts all that it Touches Isn’t Really a Sword
In his state of stupor, a memory of Master Koshiro patiently chastising him surfaces stating what seems to be a riddle which is a paradoxical conundrum that for the life of him, he cannot decipher. Koshiro states:
There are Swordsmen in this world who able to NOT cut anything.
These Swordsmen also have the ability to cut through steel.
A blade that just injures all it touches isn’t really a sword.
It really does come across as contradictory to cut and not cut, it sounds like the ramblings of a mad man.
What Koshiro is Saying & Doing?
In saying this, Koshiro also informs Zoro on the Pinnacle of Swordsmanship lies in being able to protect what one wishes and cut what one wishes. He shameless (in appearance) goes on to cut paper and fails to cut it.
Koshiro was actually giving Zoro the keys to the kingdom and the answer he wanted, but Zoro being too young was unable to comprehend his master was being literal.
His master was letting Zoro know that the Pinnacle of Swordsmanship is the ability to hit anything with a blade and choose whether it cuts or doesn’t.
By hitting paper with a sharp blade and failing to cut it, it proves that he (Master Koshiro) has reached this Pinnacle of Swordsmanship and subsequently has the power to convey his will into his blade; a blade that cannot cut anything but can also cut anything (steel in this case)
Emulating the Master
We see he used his blade to slash at a palm leaf, and what happened? It didn’t get cut – one would think that a blade that sharp would cut the palm leaf and more so if it were with Haki; this is symbolic in literal terms as to what master Koshiro did in Zoro’s youth in cutting that piece of paper .
He then goes on to slice a rock which is far more durable and sturdier than the palm leaf, yet, he cuts it like a hot knife through butter.
He’s replicated the exact feat his master did by failing to cut paper as he just did against the leaf. He’s learnt to convey his will into his blade and has reached the Pinnacle of Swordsmanship which is why he’s so confident in using one Sword to cut down Mr.1.
At this point, we see he now understands what his master was saying; the ability to not cut is the power to cut steel . It’s exactly what his master was trying to teach him, a lesson in learning how to master (or conveying your will/intentions) into your blade which is why he called it a blade that can cut, but not cut at the same time; it’s mastery over one’s blade.
Furthermore, on recognising this power, he begins to master the art of slipping into this state in order to utilise this power like Koshiro who can use this ability at will which is shown by his failure (or success rather) to not cut the paper despite hitting it implying it’s something Swordsman of high calibre should be capable of utilising.
BOAT (Breath Of All Things)
What exactly is it? If we look at the panel in the above subtitle, it tells us that he’s experienced this “breath of all things” state saying it’s like the boundary between life and death. His senses got heightened when he’s at death’s door and the main focus is on the part where he says.. “my blade understands my will” which is referring to his new-found ability to project his intentions into his blade.
I think the point being made is that in order to control and convey one’s will to their blade, one need to be able to get into this “breath of all things” state, or it’s impossible. Whilst in this state, his senses are sharpened, his instincts are elevated and he can just understand everything that’s going on around him which astonishes his opponent.
…Cut Diamond next?
After Zoro had cut Mr.1, he asks Zoro if he intends to cut at Diamonds as he’s just cut Steel. Zoro has transcended beyond that as his Swordsmanship in this battle rose to a level where he can cut anything, thus why his response to cutting Diamond as being a waste. The younger Zoro would have strove towards that goal, but Zoro has come to an understanding that this ability transcends even that.
I personally feel this state is why he’s able to materialise some of his mysterious powers such as the Asura which I presume is resultant from his cursed swords. By being able to convey intentions into his blade, the blade’s innate powers are also pulled out. On a similar note, I do wonder that if swordsmen have such a power, do sharpshooters have a similar power in the sense of conveying their will?
Cutting straight to the point for the purpose of added context, Observation Haki is limited to senses living beings as opposed to inanimate lifeless things. All instances where Observation pertinent to sensing has only been subjected and functioned against living beings such as animals and people.
Bar the ability to sense, Observation has no function in regard to physical interaction with things implying Observation has no role in regard to how to cut an opponent or anything of that nature. If anything, Armament would have been the most logical choice of powers to invoke, but it’s also unrelated in this instance.
The breathe of all things is a state whereby by immersing one’s self into a state of experience giving the sensation and feeling of being at boundary between life and death, one can reach this state. Should one be able to enter into this state willing, it makes it possible for one to convey their will into their blade enhancing their swordsmanship.
Credits – HPsyche