I thought it was going to be more broadly applicable philosophy. It was a little of that, but mostly sword technique.
You should not have a favourite weapon. To become over-familiar with one weapon is as much a fault as not knowing it sufficiently well.
Timing is important.
There is timing in your whole life, in thriving and declining, in harmony and discord.
Become acquainted with every art.
Know the Ways of all professions.
Do nothing which is of no use.
If you merely read this book you will not reach the Way.
Be determined though calm.
Do not let your spirit be influenced by your body, or your body be influenced by your spirit.
Be neither insufficiently spirited nor over spirited.
An elevated spirit is weak and a low spirit is weak.
See distant things as if they were close and to take a distanced view of close things.
Enact strategy broadly, correctly and openly.