In Buddhism, mind is what distinguishes sentient beings from rocks or trees or bodies of water. That which possesses discriminating awareness, that which possesses a sense of duality-which grasps or rejects something external-that is mind. Fundamentally, it is that which can associate with an "other"-with any "something" that is perceived as different from the perceiver. That is the definition of mind. The traditional Tibetan phrase defining mind means precisely that: "That which can think of the other, the projection, is mind."
So by mind we mean something very specific. It is not just something very vague and creepy inside our heads or hearts, something that just happens as part of the way the wind blows and the grass grows. Rather, it is something very concrete. It contains perception-perception that is very uncomplicated, very basic, very precise. Mind develops its particular nature as that perception begins to linger on something other than oneself. Mind makes the fact of perceiving something else stand for the existence of oneself.
That is the mental trick that constitutes mind. In fact, it should be the opposite. Since the perception starts from oneself, the logic should be: "I exist, therefore the other exists." But somehow the hypocrisy of mind is developed to such an extent that mind lingers on the other as a way of getting the feedback that it itself exists, which is a fundamentally erroneous belief. It is the fact that the existence of self is questionable that motivates the trick of duality. This mind is our working basis for the practice of meditation and the development of awareness. But mind is something more than the process of confirming self by the dualistic lingering on the other. Mind also includes what are known as emotions, which are the highlights of mental states. Mind cannot exist without emotions. Daydreaming and discursive thoughts are not enough. Those alone would be too boring. The dualistic trick would wear too thin. So we tend to create waves of emotion which go up and down: passion, aggression, ignorance, pride-all kinds of emotions. In the beginning we create them deliberately, as a game of trying to prove to ourselves that we exist. But eventually the game becomes a hassle; it becomes more than a game and forces us to challenge ourselves more than we intended.
So we have created a world that is bittersweet. Things are amusing but, at the same time, not so amusing. Sometimes things seem terribly funny but, on the other hand, terribly sad. Life has the quality of a game of ours that has trapped us. The setup of mind has created the whole thing. We might complain about the government or the economy of the country or the prime rate of interest, but those factors are secondary. The original process at the root of the problems is the competitiveness of seeing oneself only as a reflection of the other. Problematic situations arise automatically as expressions of that. They are our own production, our own neat work. And that is what is called mind.
According to the Buddhist tradition, there are eight types of consciousness and fifty-two types of conceptions and all kinds of other aspects of mind, about which we do not have to go into detail. All these aspects are based largely on the primeval dualistic approach. There are the spiritual aspects and the psychological aspects and all sorts of other aspects. All are bound up in the realm of duality, which is ego.
... A gigantic world of mind exists to which we are almost totally unexposed. This whole world is made by mind. Minds made this up, put these things together. Every bolt and nut was put in by somebody-or-other's mind. This whole world is mind's world, the product of mind. This is needless to say; I am sure everybody knows this. But we might remind ourselves of it so that we realize that meditation is not an exclusive activity that involves forgetting this world and getting into something else. By meditating, we are dealing with the very mind that devised our eyeglasses and put the lenses in the rims.
So this is a living world, mind's world. Realizing this, working with mind is no longer a remote or mysterious thing to do. It is no longer dealing with something that is hidden or somewhere else. Mind is right here. Mind is hanging out in the world. It is an open secret.
Like all definitions, this definition is characterized by its usefulness in a given context - in this case, the context of Buddhist views and goals. That's why words can have more than one useful definition, of course. But this kind of definition of "mind" might strike many as unusual, so maybe it can overlap with other assumptions and definitions and possibly shake something up a little bit.