To define “arcadia,” a synonym would be “paradise” or “land of ideals.” From this, you can see that the final stanza there is talking about that if others around the world were to become filled with a desire to seek paradise, human conflict would be no more. If people stopped talking to each other, there would be no disagreements, nothing to cause trouble to people. But, as seen in the earlier stanzas, this arcadia seen in dreams, is unreachable, no matter how much you try to walk towards it.
Kafka Fuura over there has his own interpretation of the final stanza that you should check out as well. By taking it as active rather than passive, the message of this song changes from focusing on Arcadia’s unreachability, to focusing on the person searching for it.
☆ Title: ARCADIA
★Album: CLOUD 9
☆ Album Artist: Alstroemeria Records
★ Vocals: mican*
☆ Arrangement: Masayoshi Minoshima
★Lyrics: Haruka
☆ Original Title: Arcadian Dream
★ Website: http://alst.net/
逃げ出した 心だけが
置いてきた 体だけを
会話すら 聞き流した
思い出す 理想だけを
nige dashita kokoro dake ga
oite kita karada dake o
kaiwa sura kiki nagashita
omoi dasu risou dake o
My heart ran off and away
it left behind only my body
and even ignored any conversation
only recalling ideals
俯かず 歩いてた
幻想の 私達
この先の 理想郷
夢に見た Arcadia
utsumukazu aruiteta
gensou no watashi tachi
kono saki no risoukyou
yume ni mita Arcadia
Looking proudly ahead we had walked on
You and I, us illusions
The arcadia beyond this point
is the arcadia I saw in my dreams
世界から 抜けられるなら
傷ついた 日々もないまま
遅らせた 歩んだ速度
遺される 貴方の為に
sekai kara nukerareru nara
kizutsuita hibi mo nai mama
okuraseta ayunda sokudo
nokosareru anata no tame ni
If we can escape from this world
even the days of being hurt will be no more
We slowed down the pace we walked
for the sake of you, becoming left behind
俯かず 歩けてた
幻想の 私達
見えるのに 遠すぎて
届かない Arcadia
utsumukazu aruketeta
gensou no watashi tachi
mieru noni too sugite
todokanai Arcadia
Without gazing down, we could walk on
You and I, us illusions
Though we could see it, it was just too far
The unreachable Arcadia
世界中 他人事ならば
傷つける 事もないのに
会話さえ 独り言なら
悩ませる 事もないのに
sekaichuu hitogoto naraba
kizutsukeru koto mo nai noni
kaiwa sae hitorigoto nara
nayamaseru koto mo nai noni
If only around the world, it were a concern of others
there wouldn’t even be such thing as hurting
If only conversations were to be soliloquy
there wouldn’t even be a thing to cause worry
Amen 