You can control nothing but your own mind.  Even your two-year-old babe may defy you by the instinctive force of its personality.  But your own mind you can control.  Your own mind is a sacred enclosure into which nothing harmful can enter except by your permission.  Your own mind has the power to transmute every external phenomenon to its own purposes.  If happiness arises from cheerfulness, kindliness, and rectitude (and who will deny it?), what possible combination of circumstances is going to make you unhappy so long as the machine remains in order?  If self-development consists in the utilisation of one’s environment (not utilisation of somebody else’s environment), how can your environment prevent you from developing?  You would look rather foolish without it, anyway.  In that noddle of yours is everything necessary for development, for the maintaining of dignity, for the achieving of happiness, and you are absolute lord over the noddle, will you but exercise the powers of lordship.  Why worry about the contents of somebody else’s noddle, in which you can be nothing but an intruder, when you may arrive at a better result, with absolute certainty, by confining your activities to your own?  ‘Look within.’  ‘The Kingdom of Heaven is within you.’  ’Oh, yes!’ you protest.  ’All that’s old.  Epictetus said that.  Marcus Aurelius said that.  Christ said that.’  They did.  I admit it readily.  But if you were ruffled this morning because your motor-omnibus broke down, and you had to take a cab, then so far as you are concerned these great teachers lived in vain.  You, calling yourself a reasonable man, are going about dependent for your happiness, dignity, and growth, upon a thousand things over which you have no control, and the most exquisitely organised machine for ensuring happiness, dignity, and growth, is rusting away inside you.  And all because you have a sort of notion that a saying said two thousand years ago cannot be practical.

You remark sagely to your child:  ’No, my child, you cannot have that moon, and you will accomplish nothing by crying for it.  Now, here is this beautiful box of bricks, by means of which you may amuse yourself while learning many wonderful matters and improving your mind.  You must try to be content with what you have, and to make the best of it.  If you had the moon you wouldn’t be any happier.’  Then you lie awake half the night repining because the last post has brought a letter to the effect that ‘the Board cannot entertain your application for,’ etc.  You say the two cases are not alike.  They are not.  Your child has never heard of Epictetus.  On the other hand, justice is the moon.  At your age you surely know that.  ’But the Directors ought to have granted my application,’ you insist.  Exactly!  I agree.  But we are not in a universe of oughts.  You have a special apparatus within you for dealing with a universe where oughts are flagrantly disregarded.  And you are not using it.  You are lying awake, keeping your wife awake, injuring your health, injuring hers, losing your dignity and your cheerfulness.  Why?  Because you think that these antics and performances will influence the Board?  Because you think that they will put you into a better condition for dealing with your environment to-morrow?  Not a bit.  Simply because the machine is at fault.