Quotes to follow from: http://www.accesstoinsight.org/lib/auth ... el365.html
By radiation is meant, as explained above, the projection of certain thoughts promoting the well-being of those persons towards whom one's mind is directed. A metta-thought is a powerful thought-force. It can actually effect what has been willed. For wishing well-being is willing and thus is creative action. In fact, all that man has created in different fields is the result of what he has willed, whether it is a city or a hydro-electric project, a rocket going to the moon, a weapon of destruction, or an artistic or literary masterpiece. Radiation of thoughts of metta, too, is the development of a willpower that can effect whatever is willed. It is not a rare experience to see diseases cured or misfortunes warded off, even from a great distance, by the application of the thought-force of metta. But this thought-force has to be generated in a very specific and skillful way, following a certain sequence.
The subjective benefit of universal love is evident enough. The enjoyment of well-being, good health, peace of mind, radiant features, and the affection and goodwill of all are indeed great blessings of life accruing from the practice of metta-meditation. But what is even more wonderful is the impact which metta has on the environment and on other beings
Near the end are some stories to support this, including the well-known tale of the Buddha stopping a raging elephant in its tracks with metta.
Now, I've also read many Buddhists online who've stated that the benefits of metta-bhavana are for the one doing the meditating -- by training the mind to be more loving and less judgmental we become ready to reach Jhanas, and so on, and the objects of meditation don't really "receive" any sort of mystical transfer of goodwill or positive energy when we "send metta" to them, though they do benefit simply from interacting with a person whose mind has been well-conditioned by metta practice.
So, I'm curious, do different teachers approach this differently?
What do you think?