By subliminal, I mean things that occur in our world that are below the threshold of consciousness but do have a psychological effect on us.

We have emotions for a reason; for instance, imagine pain. You have pain so that if you touch something that's hot, or if you slam your hand with a hammer, you will pull your hand away and not do that again.

One of the ways we interact with other human beings and form social bonds is through touch, and probably most of us are not aware of the extreme importance of touch.

Leonard Mlodinow Quotes