“Laughter is the language of the soul.”

Le rire pour l'âme et le vin pour le corps.
Le Moyen de Parvenir (1617).
Unsourced

Original: (it) Dio benedica i tatuaggi, il sesso, i baci con la lingua, gli orgasmi, il cibo e le risate senza senso.
Source: prevale.net

Source: Linden Hills

New York Times interview (1985)
Context: To me, the body says what words cannot. I believe that dance was the first art. A philosopher has said that dance and architecture were the first arts. I believe that dance was first because it's gesture, it's communication. That doesn't mean it's telling a story, but it means it's communicating a feeling, a sensation to people.
Dance is the hidden language of the soul, of the body. And it's partly the language that we don't want to show.

"Boy in Darkness," Sometime, Never (1956)

Variant: I learned that the world has a soul, and that whoever understands that soul can also understand the language of things.
Source: The Alchemist

L'accent est l'âme du discours.
English translation as quoted in A Dictionary of Thoughts: Being a Cyclopedia of Laconic Quotations from the Best Authors of the World, Both Ancient and Modern (1908) by Tryon Edwards, p. 2.

Source: The Monk Who Sold His Ferrari: A Fable About Fulfilling Your Dreams Reaching Your Destiny