<h1>He can't make a perfect circle without his arm.</h1>

<p>The mechanics of Edward's ability to transmute without a traditional circle are not that well defined. He enters the Portal of Truth and then gleans some kind of knowledge about alchemy that allows him to do this. He probably couldn't tell you why he needs both arms, he just knows that he does. </p>

<p>That said, we can try to make an educated guess.</p>

<p>While it's true that he could make a "circle" by putting his arm on his shoulder or other part of his body, this wouldn't serve as a true transmutation circle. </p>

<p>Almost every transmutation circle we see in the series has a single common property: symmetry. 
<a href="https://i.sstatic.net/dmAaDm.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/dmAaDm.jpg" alt="An example of a transmutation circle"></a>
<a href="https://i.sstatic.net/T7NNc.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/T7NNc.jpg" alt="Al&#39;s Blood Seal"></a></p>

<p>Though this symmetry isn't perfect, with the symbols being different in the circle on the left and Al's Blood Seal on the right having that slightly asymmetrical circle in the middle, for the most part, the circles are perfectly symmetrical, especially the borders and the "structure" within. </p>

<p>If Edward tried to make a circle with one arm, he would have an awkward and asymmetrical circle.</p>

<p><a href="https://i.sstatic.net/s2sI0.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/s2sI0.jpg" alt="Edward plz"></a></p>

<p>When he uses both arms, though, he is able to make a (roughly) symmetrical circle, and perform a transmutation.</p>

<p><a href="https://i.sstatic.net/8w7gu.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/8w7gu.jpg" alt="Still short though."></a></p>

<p>You also mentioned:</p>

<blockquote>
  <p>... why can't he make a circle between his functioning flesh arm and his non-functioning automail arm?</p>
</blockquote>

<p><strong>I don't see why he couldn't.</strong></p>

<p>He never really got a chance to do this, though.</p>

<p>As far as I can remember, the only time his arm was not working, yet completely intact and attached to his body, was right after the fight with the Slicer brothers when Envy and Lust showed up in the 5th Laboratory. </p>

<p>When his arm broke, he was freaking out, and he had also lost a lot of blood, so I doubt he was thinking clearly. Envy knocked him out before he was really able to try anything. Also, his arm breaking was probably a bit for comedic purposes too. </p>

CC BY-SA 4.0
2018-08-30T16:14:14.487Z
2018-08-30T16:14:14.487Z
Chrygore
<p><a href="https://anime.stackexchange.com/questions/24356/if-you-had-two-automail-arms-could-you-still-use-alchemy?rq=1">This answer</a> establishes that all that's needed for a person who's seen the Gate to perform alchemy is to be able to make a circle with their body. However, Ed doesn't seem to be able to perform alchemy without his automail arm working.</p>

<p>Why can't he, for example, make a circle between his flesh arm and his shoulder/port and do alchemy that way? Or, alternatively, why can't he make a circle between his functioning flesh arm and his non-functioning automail arm?</p>

<p>Is there any canon explanation for this, or does it seem to be just a plot excuse for his automail arm being broken stopping him from doing alchemy?</p>

CC BY-SA 3.0
2018-02-23T19:42:35.427Z
This is only my opinion, but Edward himself might think he has to touch his palms together to make Alchemy function. As the number of people who can perform alchemy without a circle is pretty scarce and Ed is the only one with an automail the option never might have occured to him. It's also possible the circle created by touching his own shoulder wouldn't work at all because it's shape is asymmetrical. But again, this is only my guesswork and I don't remember the topic ever being touched in the manga,
Gorzius
CC BY-SA 3.0
2018-02-26T02:05:05.190Z
@Gorzius Well, but based on the other answer, all that is really needed is the circular seals created by pressing flesh (or, in Al's case, fabric) against something, and doing that with hands is enough. So, the shape of the arm wouldn't matter, but the shape of the contact points where his hand presses against his shoulder. Even when he presses his palms together, his arms don't create a circular shape, since his hands are close to his chest, so the arms are more oval/rectangular in shape
Remy Lebeau
<fullmetal-alchemist-series>
Why can't Ed perform alchemy without his arm?
# Why can't Ed perform alchemy without his arm?
Posted by: username_0 on 2018-02-23
[This answer](https://anime.stackexchange.com/questions/24356/if-you-had-two-automail-arms-could-you-still-use-alchemy?rq=1) establishes that all that's needed for a person who's seen the Gate to perform alchemy is to be able to make a circle with their body. However, Ed doesn't seem to be able to perform alchemy without his automail arm working.

Why can't he, for example, make a circle between his flesh arm and his shoulder/port and do alchemy that way? Or, alternatively, why can't he make a circle between his functioning flesh arm and his non-functioning automail arm?

Is there any canon explanation for this, or does it seem to be just a plot excuse for his automail arm being broken stopping him from doing alchemy?
**Tags:** fullmetal-alchemist-series
> **Comments:**
> **username_1**: This is only my opinion, but Edward himself might think he has to touch his palms together to make Alchemy function. As the number of people who can perform alchemy without a circle is pretty scarce and Ed is the only one with an automail the option never might have occured to him. It's also possible the circle created by touching his own shoulder wouldn't work at all because it's shape is asymmetrical. But again, this is only my guesswork and I don't remember the topic ever being touched in the manga,  
> **username_2**: @Gorzius Well, but based on the other answer, all that is really needed is the circular seals created by pressing flesh (or, in Al's case, fabric) against something, and doing that with hands is enough. So, the shape of the arm wouldn't matter, but the shape of the contact points where his hand presses against his shoulder. Even when he presses his palms together, his arms don't create a circular shape, since his hands are close to his chest, so the arms are more oval/rectangular in shape  
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## 1 answers
### Answer by username_3 on 2018-08-30. Score: 3
# He can't make a perfect circle without his arm.

The mechanics of Edward's ability to transmute without a traditional circle are not that well defined. He enters the Portal of Truth and then gleans some kind of knowledge about alchemy that allows him to do this. He probably couldn't tell you why he needs both arms, he just knows that he does.

That said, we can try to make an educated guess.

While it's true that he could make a "circle" by putting his arm on his shoulder or other part of his body, this wouldn't serve as a true transmutation circle.

Almost every transmutation circle we see in the series has a single common property: symmetry.
[![An example of a transmutation circle](https://i.sstatic.net/dmAaDm.jpg)](https://i.sstatic.net/dmAaDm.jpg)
[![Al's Blood Seal](https://i.sstatic.net/T7NNc.jpg)](https://i.sstatic.net/T7NNc.jpg)

Though this symmetry isn't perfect, with the symbols being different in the circle on the left and Al's Blood Seal on the right having that slightly asymmetrical circle in the middle, for the most part, the circles are perfectly symmetrical, especially the borders and the "structure" within.

If Edward tried to make a circle with one arm, he would have an awkward and asymmetrical circle.

[![Edward plz](https://i.sstatic.net/s2sI0.jpg)](https://i.sstatic.net/s2sI0.jpg)

When he uses both arms, though, he is able to make a (roughly) symmetrical circle, and perform a transmutation.

[![Still short though.](https://i.sstatic.net/8w7gu.jpg)](https://i.sstatic.net/8w7gu.jpg)

You also mentioned:

> ... why can't he make a circle between his functioning flesh arm and his non-functioning automail arm?

**I don't see why he couldn't.**

He never really got a chance to do this, though.

As far as I can remember, the only time his arm was not working, yet completely intact and attached to his body, was right after the fight with the Slicer brothers when Envy and Lust showed up in the 5th Laboratory.

When his arm broke, he was freaking out, and he had also lost a lot of blood, so I doubt he was thinking clearly. Envy knocked him out before he was really able to try anything. Also, his arm breaking was probably a bit for comedic purposes too.
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