In plain words
When he goes on pardoning all who do wrong, showing compassion to all the wicked and looking on them kindly, his way of ruling goes wholly astray. As the goad is the support, the chief thing, for the elephant, as the bridle is so important for the horse, so is punishment just as important for a wrong. Without that punishment there is no protection at all. So in human life we may take some thoughts to be noble. We may believe some thoughts to be bad; but the effects of good and bad depend on the mind. So when the mind holds to a pure, unselfish feeling, everything turns out good. That is why we have to examine very finely the working of thoughts too. It is very hard for us to believe in the form of these thoughts as a physical, natural thing.
When we let our thoughts arise pure, with no evil feelings in the heart, and foster the thought, ‘lokāsamastā sukhino bhavantu’, may all be well, everything turns out good. So the moment our thoughts are born, we must enquire whether they are good or bad. If we keep developing only bad thoughts in our citta, our very life enters the bad path. When we look well into each small matter, we can recognise the truth of it: is this harm done to others, or harm one does to oneself? Today we have decided to give a dinner for two friends. But it is not for those two alone; we too eat that dinner. But what we think is that it was done for others. But what was done for others, we enjoy too. In the same way with harm: the thought we dwell on for others comes to us as well. It torments us too. We resolve that a country should perish. But since we too are in that country, along with the country we too have to perish.
But though a thought is one, it takes on many forms. Within a single thought many thoughts arise.