How to Read “Mouth is mouth, heart is heart”
Kuchi wa kuchi, kokoro wa kokoro
Meaning of “Mouth is mouth, heart is heart”
“Mouth is mouth, heart is heart” means that what you say with your mouth and what you think in your heart are separate things. This proverb warns against such insincere behavior.
You might speak kind words on the surface while thinking something completely different inside. Or you might agree verbally while actually feeling the opposite.
This proverb points out such inconsistency between words and feelings. It teaches that this behavior damages trust in relationships.
People mainly use this saying to criticize someone’s insincerity. For example, “That person is mouth is mouth, heart is heart, so I can’t trust them.”
It criticizes attitudes where surface and reality don’t match. You can also use it as a warning to yourself: “I’ll stay honest and not become mouth is mouth, heart is heart.”
Even in modern society, this disconnect happens often. Some people write positive things on social media but act differently in real life.
This proverb continues to serve as a warning against such insincerity.
Origin and Etymology
The exact first appearance of this proverb in literature is unclear. However, its structure shows the refined sensitivity Japanese people have toward interpersonal relationships.
The parallel structure of “mouth is mouth, heart is heart” is a traditional Japanese expression technique. It places two things side by side to emphasize that they are separate.
By repeating the same words with the particle “wa” between them, the phrase highlights that they are “different things.”
This expression likely emerged from the Japanese cultural concept of “tatemae and honne” (public face and true feelings). In a society that values group harmony, directly expressing your true feelings isn’t always considered appropriate.
However, this proverb doesn’t simply affirm that culture. Rather, it warns against the “insincerity” of having your words and heart differ.
People have long recognized the danger of words and heart not matching in relationships. This saying has been passed down as a caution against those who say good things while thinking differently inside.
It also serves as a warning to ourselves about such behavior.
Usage Examples
- He is mouth is mouth, heart is heart—he praises people to their faces but apparently badmouths them behind their backs
- I want to live honestly with my true feelings, so I don’t become mouth is mouth, heart is heart
Universal Wisdom
The proverb “Mouth is mouth, heart is heart” reveals the complexity of human nature and its dangers. Why do people separate what they say from what they think?
It’s because humans are social creatures. We live within relationships with others. Sometimes we hide our true feelings to maintain harmony in the moment.
We don’t want to hurt others, be disliked, or cause trouble. From such thoughts, we learn to distinguish between true feelings and social facades.
However, this proverb warns against the danger of this separation becoming habitual. When insincerity becomes normal, problems arise.
When mouth and heart drift too far apart, you eventually lose track of what you truly think. The foundation of trust in relationships crumbles.
Our ancestors deeply understood this human trait. Everyone experiences the conflict between true feelings and social facades.
But they also saw the truth that going too far means losing your integrity as a person. This proverb continues to convey, in simple words, both the difficulty of being human and the importance of striving for honesty.
Times change, but the workings of the human heart don’t. That’s why this teaching still resonates with us today.
When AI Hears This
When you view human language as a communication channel, an interesting contradiction emerges. Words from the mouth are high-speed communication that can transmit about 300 words per minute.
However, this high-speed channel easily mixes in “intentional noise”—lies and social pleasantries. Meanwhile, true feelings transmit only through low-speed channels like subtle facial changes or voice tone.
These channels are harder to falsify because they emerge unconsciously, making them more reliable.
In communication engineering, there’s a principle that channels that send information faster and in larger quantities are more susceptible to noise. Fiber optics are fast, but tiny refractions cause errors.
Human relationships have exactly the same structure. Words as a high-speed channel are convenient, but the sender can intentionally alter the data.
So we as receivers observe multiple channels simultaneously and perform error correction. We compare the content of words with low-speed channels like facial expressions and gestures.
When we find contradictions, we judge “that’s not their true feeling.”
This proverb shows that humans instinctively perform “redundant multi-channel communication.” One channel alone can’t reveal the truth.
So we unconsciously integrate multiple signals from others, trying to read the real message while removing noise.
Lessons for Today
This proverb teaches you that honesty is the foundation of relationships. Now that social media has developed and we can easily broadcast words, matching mouth and heart matters even more.
Of course, you don’t need to bare your true feelings in every situation. Choosing your words out of consideration for others is also an expression of kindness.
However, if you habitually say things different from your true feelings, you’ll eventually lose track of what you really feel.
What matters is being honest with your own heart. Before putting something into words, pause and check your true feelings.
Then make an effort to choose words that align with those feelings as much as possible.
Sometimes being honest requires courage. But that courage helps you grow into a trustworthy person.
People whose mouth and heart match give others a sense of security. They can build deep relationships of trust.
You don’t need to be perfect. Just maintaining an attitude of trying to be sincere will enrich your life.
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