If he is happy he will dance about as naturally, and almost as inevitably, as the leaves dance when the breeze passes through them.
We will call this the _musical instinct_.

So elemental is it that man shares it, in some degree, with other living things.

The birds are accomplished musicians, and their movements, and those of many other creatures, are full of rhythm and grace.
In both these instincts the child is struggling to grow, to expand his being, by going out of himself, in response to the attractive force of beauty, into that larger life which is at the heart of Nature, but which is not ours until we have made it our own.

We will therefore call these the _AEsthetic Instincts_, and place them in a class by themselves.
(5) From a very early age the child desires to know the why and wherefore of things, to understand how effects are produced, to discover new facts, and pass on, if possible, to their causes.

In response to the pressure of this instinct, the child breaks his toys in order that he may find out how they work, and asks innumerable questions which make him the terror and despair of his parents and the other "Olympians." No instinct is more insistent in the early days of the child's life.