The Process of Consciousness and Matter, by the late Dr. Rewata Dhamma, is now available as a free ebook from the Pariyatti Treasures website.
Venerable Rewata Dhamma was one of the foremost scholars of Abhidhamma in modern times. He co-authored an introduction to the classic text, A Comprehensive Manual of Abhidhamma, to which The Process of Consciousness and Matter serves as a supplement.
Intended for all serious students of the Abhidhamma, this work treats various important aspects in more detail. In the introduction Ven. Rewata Dhamma writes "As human beings our sense consciousnesses, occurring at each of our five sense doors, arise and pass away millions of times each second. It needs to be understood that, because there are several sense doors there is not just one process occurring, there are many. Thus, for example, as we sit in meditation we may be experiencing many processes, such as feeling contact with the ground, and also seeing, hearing and so on. However, the sense consciousnesses themselves are not occurring simultaneously, even though it may seem that they are happening in the same mind moment. They seem to be happening simultaneously only because they follow one after the other at such an incredibly rapid rate. Therefore, I first of all explain that the processes arising at the five sense doors arise in respect of their own different respective objects. I then explain how the sense object consciousness arises at each sense door. . ."
Born in Burma in 1929, he obtained his Ph.D. from Varanasi University, India, in 1967. That year he also edited and published the two-volume Abhidhammattha Sangaha. Venerable Rewata Dhamma passed away in 2004.