One way to train ourselves to cheerful views of life is resolutely to refuse to be frightened at shadows, or even to see trouble where there is none. Half or more of the things that most worry us have no existence save in a disordered fancy. Many things that in the dim distance look like shapes of peril, when we draw near to them, melt into harmless shadows, or even change into forms of friendliness. Much of the gloomy tinge that many people see on everything is caused by the colour of the glasses through which they look. We sit behind our blue glass windows, and then wonder what makes everything blue. The greater part of our discontent is caused by some imaginary trouble which never really comes