Dualistic Consciousness?

I have been getting puzzled and confused about an apparent contradiction in Matthieu Ricard's treatment of consciousness in The Quantum and the Lotus. On the one hand is the idea of shunyata, or none-ness (=one-ness), by which there is, in one sense, no notion of a true separation between things out there. Since there is just interdependence, all phenomena can be seen as just one, and "... ultimately, phenomena have no intrinsic existence"[pg. 28]. But, when it comes to consciousness, it suddenly seems to go dualistic:

"... cause and effect must have a common nature, when the cause is substantially [as opposed to cooperatively] responsible for the effect. ...A moment of consciousness can only be caused by a preceding moment of consciousness. If something can be born from something utterly different, then anything could be born from anything else. Thus the fundamental level of consciousness cannot have arisen from inanimate matter, and it doesn't necessarily and in all contexts, depend on being embodied in a physical form."

So is this dualism? Thuan asks Matthieu precisely this question:

Matthieu: "Buddhism's conception is radically different from Cartesian dualism. We believe that there's merely a conventional difference between matter and consciousness because, in the end, neither of them has an inherent existence. Because Buddhism refutes the ultimate reality of phenomena, it also refutes the idea that consciousness is independent and exists inherently."

So, the key to the puzzle (which, had I read the texts more carefully, is there right from the start), is the difference between relative or conventional truth and absolute truth. In the absolute sense, there is no difference between matter and consciousness. But in the relative or conventional sense, there is. But why should consciousness be separated from the material in the relative sense? Buddhists see causation as arising from two things - substantial causes and cooperative conditions. E.g., for a flame, the burning fuel is the substantial cause of the flame, and the atmosphere etc. that make it possible are the cooperative conditions that allow the combustion of the fuel. However, the causes and effects must have 'similar natures', for otherwise anything could be the (substantial) cause of anything else {Note: I think I might prefer to refer to it as a substantial, immediate cause}. And, in the Buddhist theory, material things, because of their qualities like having a location in space and being measurable, do not accord with them being the causes of consciousness. In this view, then, the brain is a cooperative condition for consciousness, rather than a substantial cause. And how does one know this? Well, that's part of the come-and-see bit. You have to do their "math", which is meditation and all that. It's a bit like needing to learn about tensors in order to work through a mathematical understanding of general relativity. Or, you could just believe that Einstein and his crowd (or Siddhartha and his crowd) did the math right... ;)