Smiling is at the root of who we are as human beings. In fact, it's the very first thing parents take pride in when they monitor their infant's development.

A baby, long before it even begins to communicate verbally and physically, feels the message of a smile instinctively and almost always responds in kind.

Rabbi Yisrael Salanter taught that the face of a person is considered public property and one should always smile at everyone. A sour face can damage the mood of others and we are never allowed to inflict damage to others. How much happier would the world be if we all smiled at each other?

This is exactly what Ethics of the Fathers (5:15) has in mind when it says "Accept all people with a pleasant face."

Have you ever wondered why it is that when we wish to show warmth and friendliness to another person, we instinctively smile and reflexively display our teeth? If we were creating the body would you suggest opening your mouth and showing your teeth as a way to show friendship? Why did God make our bodies react in this manner? Why is displaying our teeth associated with being open and pleasant?

A hint may be found in the following Midrash about teeth.

Just as the strength of a person is held within his teeth (if one has no teeth or weak teeth, he cannot eat, and gain strength -ed.), so too, the strength of the Jewish people is found within the Torah. (Yalkut Shimoni)

Teeth are linked here to wisdom.

According to mystical sources there are 32 paths of wisdom. So too there are 32 sources of wisdom within a person (found in the head) which are channeled to each one of the entire set of 32 adult teeth. The number 32 has the numerical value, gematria, of the Hebrew word lev, which means heart. This means that our 32 teeth represent what is in our heart.

Teeth are linked to the heart and to wisdom. What does this all mean?

Smiling is a symbol of our willingness to open ourselves up to others.

The wisdom of a human being begins with thoughts in the heart, but if it remains there the wisdom is self-serving. In order for that wisdom to make the world a better place it needs to be expressed through the mouth. When we open our mouths and speak we share ourselves with the world. Smiling is a symbol of our willingness to open ourselves up to others.

Our many teeth represent the many thoughts that run through our heads; thoughts which have the potential to help others, to make a positive impact upon those around us and indeed the entire world. When we open our mouths and smile at someone we are communicating the following message: "I want to show you what is inside of me." When we smile and display our teeth, we are showing others that there's a lot inside that we want to share.

Whether we realize it or not, when we smile we are showing a glimpse of our wisdom. God created us so that when we are happy we smile, we laugh, we show our teeth. This is as if to say, "I am in a wonderful mood. I feel the grandeur of life. I am happy to be alive in this world. Thus, I am showing my teeth to the world -- and through my teeth, I am displaying my wisdom. I have a precious role to play in this world by tapping into and utilizing my wisdom and sharing it with others. This is why I'm smiling; this is the reason I am showing you my teeth."

When we greet someone, we are supposed to smile at them. Smiling exhibits our kindness and openness to relate to another person. When I frown I close my mouth tightly; I hide my teeth. I am saying that I do not wish to open myself or my wisdom up to anyone. But when I smile, I say to my fellow man, "Yes, I want to get to know you. I want to share my wisdom, my insights, my personal contributions to this world with you. I am showing you my teeth, the window to my world and my wisdom, and I want you to partake in what I have to offer."

As Denis Waitley said, "A smile is the light in your window that tells others that there is a caring, sharing person inside."