What is loud and shining and unusual attracts our involuntary attention.

We must turn our mind to a place where an explosion occurs, we must read the glaring electric signs which flash up.

To be sure, the perceptions which force themselves on our involuntary attention may get their motive power from our own reactions.

Everything which appeals to our natural instincts, everything which stirs up hope or fear, enthusiasm or indignation, or any strong emotional excitement will get control of our attention.

But in spite of this circuit through our emotional responses the starting point lies without and our attention is accordingly of the involuntary type.