I love how long Musashi has been thinking of the strategy that went into this book:

“When I reached thirty I looked back on my past. The previous victories were not due to my having mastered strategy. Perhaps it was natural ability, or the order of heaven, or that other schools’ strategy was inferior. After that I studied morning and evening searching for the principle, and came to realise the Way of strategy when I was fifty.”

He spent his whole life mastering the craft, and then summarized his lessons so concisely and eloquently.

Musashi compares learning with being a carpenter, the teacher cannot force learning on the student, and the student cannot learn in isolation: “The teacher is as a needle, the disciple is as thread. You must practice constantly.”

In combat, Musashi would typically use two swords, one short and one long. He touches on the importance of using all of your weapons in combat and life: “This is a truth: when you sacrifice your life, you must make fullest use of your weaponry. It is false not to do so, and to die with a weapon yet undrawn.”

“It will seem difficult at first, but everything is difficult at first. Bows are difficult to draw, halberds are difficult to wield; as you become accustomed to the bow so your pull will become stronger. When you become used to wielding the long sword, you will gain the power of the Way and wield the sword well.”

“Anyway, if you learn “indoor” techniques, you will think narrowly and forget the true Way. Thus you will have difficulty in actual encounters.”

I love this idea : “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.”

Musashi breaks the book into five books: Ground, Water, Fire, Wind, and Void

Ground

Musashi describes the essence of the ground book as the foundation of the other books. “Know the smallest things and the biggest things, the shallowest things and the deepest things. As if it were a straight road mapped out on the ground, the first book is called the Ground book.”

Water

"With water as the basis, the spirit becomes like water. Water adopts the shape of its receptacle, it is sometimes a trickle and sometimes a wild sea."

He also talks about fundamental knowledge in this book: "The principle of strategy is having one thing, to know ten thousand things."

A core lesson of water is to stay calm and even-keeled: "Both in fighting and in everyday life you should be determined though calm. Meet the situation without tenseness yet not recklessly, your spirit settled yet unbiased. Even when your spirit is calm do not let your body relax, and when your body is relaxed do not let your spirit slacken. 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. Do not let the enemy see your spirit."

Combat is life, you cannot keep them separate: "In all forms of strategy, it is necessary to maintain the combat stance in everyday life and to make your everyday stance your combat stance. You must research this well."

Maintain your ability to zoom out and zoom in, don't be lost in the trees or the forest: "In strategy it is important to see distant things as if they were close and to take a distanced view of close things."

Focus on victory over yourself first: "Study strategy over the years and achieve the spirit of the warrior. Today is victory over yourself of yesterday; tomorrow is your victory over lesser men."

Fire

"The essence of this book is that you must train day and night in order to make quick decisions. In strategy it is necessary to treat training as part of normal life with your spirit unchanging."

The three methods to forestall the enemy:

1. Forestall by attacking
2. Forestall by responding to his attack by feigning weakness, then attacking
3. Forestall by attacking when he attacks and meeting him head on

Maintain control of your position, don't be led about: "In contests of strategy it is bad to be led about by the enemy. You must always be able to lead the enemy about."

If you can't see the enemy's resources, feign a strong attack to see his response: "In large-scale strategy, when you cannot see the enemy’s position, indicate that you are about to attack strongly, to discover his resources. It is easy then to defeat him with a different method once you see his resources."

Wind

"This book is not concerned with my Ichi school but with other schools of strategy. By Wind I mean old traditions, present-day traditions, and family traditions of strategy.”

In my Ichi school of the long sword there is neither gate nor interior. There is no inner meaning in sword attitudes. You must simply keep your spirit true to realise the virtue of strategy.

Void

“By void I mean that which has no beginning and no end. Attaining this principle means not attaining the principle. The Way of strategy is the Way of nature. When you appreciate the power of nature, knowing rhythm of any situation, you will be able to hit the enemy naturally and strike naturally.”