David Bohm worked closely with Einstein and Oppenheimer and is known as one of the world's foremost theoretical physicists. His Causality & Chance in Modern Physics is a classic in quantum mechanics. Other works include: Thought As A System, On Dialogue, Wholeness and the Implicate Order, The Undivided Universe and Science, Order & Creativity with David Peat.

Thought is not separate from perception. In fact, thought also is not separate from feeling because thought can induce feelings. The thought that somebody treated me badly can induce anger or thoughts can induce feelings from memory. In order to understand this further we should make a distinction between thinking and thought. Thought is the past participle of something that has been done. Thinking is going on right now.

We tend to think that feelings are always active because the word feeling is active, but we could imagine the word felt, introduce the word felt and say besides thinking and thought, there are feelings and felts. There are direct feelings, which you get when you see something or experience something.

Then there are feelings that come from memory. Those feelings however may not be seen as feelings that are coming from memory. They're experienced as actually the same as direct feelings, just as our representations are experienced as direct perception. That confusion is very serious because it will lead us to try to deal with our projections and representations as if they were real.

It seems that this confusion comes when we fail to notice that an emotion or feeling is actually not coming from the present experience, but rather from something we have felt in the past. The source is really coming from our memory.

Thought is the activity of the past and the present. Thought is the past. We can understand thought as a conditioned reflex. We could take the example of Pavlov and his dog. The dog has a natural reflex. When it sees food it salivates when it's hungry. If you ring a bell many times every time it sees food, it will then salivate when you ring the bell. Perhaps ringing the bell is associated to the memory of perceiving the food and then salivation occurs. Eventually it skips the stage of perceiving the food so you'll get a conditioned reflex. I say thought works like a conditioned reflex. When you think something, when you have thought something, it leaves something in the memory and that something reacts according to the situation by our association.

Is thought always the past projecting itself into the present and is this what you call a reflex?

Yes, but it's constantly changing because every experience goes into the past. Whatever you learn goes into the past and becomes thought. As the reflex gets more and more automatic it becomes more thought and less and less intelligent, less and less adapted to the particular situation. We tend to fall back into automatic reflexes.

To grasp what you are saying we need to distinguish between a direct perception and the mechanical activity of our thoughts.

For the moment I'd say that perception is the ability to perceive something new, which is not contained in memory. The most elementary perception is sense perception. You can see where things are, although memory enters into the way that perception is organized, there must be something in there, which is not just memory.

When we open our eyes and see something - this is one aspect of what you are calling sense perception?

Very often people see so automatically that they hardly notice anything. It has essentially no perception or very little. Or with more attention they pay, the more of a quality of perception comes in. But thought is more than that. Thoughts introduced feelings and felts. From a thought there can be an association which gives rise to a felt and that may in turn give rise to more thought and that may affect perception.

So we have our direct sensory perception and also past feelings or what you call felts and they seem to combine somehow to give us this impression of reality. There is also what we call intellect, which plays a role as well.

To call thought just the intellectual part will not be adequate. The feelings which come are associated with and also part of the same process. Everything which is the response of memory should be put together and called by one name and thought is about the best and the most characteristic name.

You describe how these physical, emotional and intellectual patterns become layer upon layer of memory, which then repeat themselves.

We do need repeated patterns but the question is whether the repeated patterns will dominate or whether something else comes in which is more intelligent. It's clear that the repeated pattern does not have intelligence. Its ability to adapt to new circumstances is limited. People have compared that pattern to a computer program. I think that's not a good comparison. A program would be something that had been laid down beforehand. If somebody had planned it out, but these conditioned reflexes, are built up through experiences. They are not pre-programmed. Nobody has put them in.

These habits or reflexes become very strong and yet very subtle. Can you describe how they are built up in the system?

For example, if you have the emotion of anger, this is induced by thought. If somebody keeps you waiting for a couple of hours and then suddenly comes in, you'll be getting more and more angry saying he has treated me badly, he doesn't have any respect for me and wastes my time. By thinking that way you can build up very powerful feelings of anger, the adrenaline can build up and all the neuro chemicals. But if he gives a good excuse then it suddenly goes, right? If he doesn't give a good excuse or if it's a false one it will get worse.

Similarly by thinking thoughts of things that are pleasant or things that appeal to you, could induce those feelings, that state of chemistry. And you can induce fear by thought, by thinking of things that are dangerous. So the thoughts and the emotions are not separate. Nor is the tension in the body, which is also part of the process.

All our systems of organizing society are an extension of thought. There's hardly anything in the world that we see or experience that is not an organization of thought. So it's all part of the system. There's one system. It doesn't stop inside a human being. It goes from one person to another, all through society, all through history, all over the world. The ecological problem is the result of the way we have been thinking about the world, that it's something we can exploit indefinitely and we're still thinking that way& .