This website is about the "law of attraction". Sorry, this is NOT science. It is psuedoscience that would like to characterize itself as science. It is much like religion in that it is a system of blaming the victim. Just been brutally beaten? Depending on your belief system, it's because it's karma, you did something to deserve it, God doesn't love you, you didn't pray enough, or (law of attraction) you attracted it by thinking negative.
Positive thinking can make a person feel better simply b/c they have a better outlook. It can give a person confidence to try things they otherwise wouldn't, and not feel so terrible if things don't work out. Negative thinking, however, has important purposes too: preparing people for all possibilities and thinking realistically. People's thoughts can show through in their attitudes and things they say unintentionally, but a person's thoughts alone do not influence outside matter.
I prefer to think in terms of productive and non-productive thinking. Negative thinking is not productive when a person is surrounded by a cloud of futility. Positive thinking is not productive when a person is out of touch with reality and thinks that just by daydreaming about how much weight they're going to lose, they'll lose weight with no effort (actual strategy from The Secret).
Well the science of thought is really still in it's infancy, but there have been many philosophies dealing with mental states, Sanskrit is said to have many words describing subtle states of mind - and this makes sense when considering the focus of Vedic culture was on inner wisdom and strength.
Then there's this:
I guess I really need to buy some satin underpants ^^