Be Vigilant; Guard Your Mind Against Negative Thoughts. -Buddha

Even those who wish to find happiness and overcome
misery,
Will wander with no aim nor meaning,
If they do not comprehend the secret of the mind-
The paramount significance of Dharma.

This being so,
I shall hold and guard my mind well.
Without the discipline of guarding the mind,
What use are many other disciplines?

Just as I would be attentive and careful of a wound
When amidst a bustling uncontrolled crowd,
So I should always guard the wound of my mind
When dwelling among harmful people.

And if I am careful of a wound
Through fear of it being slightly hurt,
Then why do I not guard the wound of my mind
Through fear of being crushed by the mountains of hell?

Should I behave in such a way as this,
Then whether among harmful people
Or even in the midst of women,
The steady effort to control myself will
not decline.

It is better to be without wealth,
Honour, body and livelihood;
And it is better to let other virtues deteriorate,
Rather than ever to let ( the virtues of) the mind decline.

O you who wish to guard your minds,
I beseech you with folded hands;
Always exert yourselves to guard
Mindfulness and alertness!

-Shantideva, The Way of the Bodhisattva