"Iron rusts from disuse; water loses its purity from stagnation... even so does inaction sap the vigor of the mind"

This quote by Leonardo da Vinci is a reminder of the importance of action and motion in life. He is recommending that if we do not utilize something, it will ultimately spoil. In the exact same way, if we do not utilize our minds, our psychological vigor will diminish. He is alerting us that if we do not do something about it, our minds will become stagnant and our psychological capability will suffer. He is emphasizing the importance of staying active and participated in life, both physically and mentally. He is recommending that if we do not utilize our minds, our psychological capacity will suffer and our minds will pall and unproductive. He is advising us that if we do not utilize our minds, our psychological vigor will be lost. He is encouraging us to stay active and engaged in life, both physically and psychologically, in order to keep our minds sharp and our psychological capacity strong.