They are not material things; they are not made of atoms or anything physical. Yet our thoughts clearly exist. What, then, is their essential substance?
Because we don’t often consider this question we don’t have any ready words for the “stuff” from which mental phenomena are made. Perhaps the best we can say is they are made from mind-stuff. That doesn’t in itself say much, except to emphasize that they are not made of matter-stuff.
One might say that the stuff of the mind is consciousness. But some caution is needed here. The word “consciousness” has various meanings and my idea of it may be different from yours.
In addition it is a noun, which implies it is some “thing.” And is therefore something that can be known in some way, however subtle—another object of knowing, rather than that which knows all experiences.
The word “conscious” derives from the Latin con-scius—literally, “with knowing.” The suffix “ness” in conscious-ness means “the state or quality of.” It is appended to an adjective to create an abstract noun that allows us to talk about that quality in a general way. Happiness is the state of being happy. Softness is the quality of being soft. But neither happiness nor softness exists as an independent “thing”. Similarly there is no such “thing” as consciousness. The word refers to “the state or quality of” being conscious—of being “with knowing.”
So one could say the common essence of all thoughts is the knowing of them. They are made of knowing.
An analogy is often drawn with waves in water. A wave is just water in motion. It does not exist as an independent entity, separate from the water. It is merely the way the movement is perceived.
Similarly, our thoughts are ripples of knowing, which are experienced as words in my mind, with perhaps some image from the past and maybe an associated feeling. But the thought has no independent existence beyond my knowing of it. It is but a temporary ripple in the ever-present field of knowing.
The same is true of any other experience that may appear in the mind. The images that constitute a memory are all “in the mind,” and are likewise just modulations of the field of knowing. So too are the scenes we experience when we imagine the future.
It is only a short step to appreciate that the same applies to our experience of the material world. If you close your eyes and explore your experience of your body, you will find various sensations—some pressure in places, some warmth here, a tingling there, or some tension perhaps. These too are but ripples in the field of knowing. The different sensations become integrated into the experience of having a body. But, like the various sensations, this experience of a body is another modulation of the field of knowing.
Similarly with sound. It is easy to appreciate this when we imagine some music. That clearly is an experience arising in the mind. There is no essential difference with “live” music. The brain is taking the data relayed to it from the ears, and from that creating the sound of music. This is experienced as coming from an external world beyond the body, but that experience is itself still arising in me, another excitation of the field of knowing.
As information from other senses is added in, our mental representation of the world begins to take on the mantle of an independent reality. We begin to believe that the world arising in our awareness is the world out there—the so-called “real” world.
This is made all the more convincing as soon as we open our eyes.
Vision takes us out into the world of an apparent external space that seems to be independently real and filled with material objects. But however much it may appear so, we are forced to accept that the visual experiences themselves are also just ripples of knowing.
This is where it begins to get mind-bending. We may realize that the colors we experience are just appearing in the mind—the light itself is not colored, it is simply energy of varying frequencies, the color we experience coming from the representation of that frequency in the mind—but it is more difficult to appreciate the same is true of the solidity we experience around us. It not only looks solid, we can touch it, feel its solidity, and experience how it impedes our movement. We seem to be experiencing the world directly, but in truth all that we are experiencing, including its apparent solidity, is a representation of the world “out there” appearing in our field of knowing. It is how the information that the senses detect appears in the mind.
We can explore this representation in the mind, and from that draw conclusions about the nature of the physical world—which is what science aims to do—but all that we discover, all that we know and understand about the world, all our scientific theories and mathematical equations, our concepts of matter, energy, space and time, our notions of quarks, strings, particles and waves, are but appearances in the mind, more ripples in the field of knowing.