Dalai Lama: Generally speaking, there are two ways of coming to such a conclusion. One is through logical reasoning and the other is from seeing that if consciousness did have a beginning and an ending, a lot of contradictions and mysteries could not be explained. So, since the latter viewpoint has many inconsistencies, we can arrive at the conclusion that it must be the other way around i.e. that consciousness is without beginning or end.
On this question I think it is also important to understand that there are three types of phenomena — one is phenomena which can be directly observed, the obvious phenomena, the second is the slightly concealed phenomena which could be realised through the reasoning process, and the third is the very concealed phenomena.
I think it is also important to understand that there are different ways of observing these phenomena. Buddha spoke of the law of nature which includes such factors as consciousness, or mind, being the nature of luminosity and knowing. Why is consciousness in nature? There is no reason. In the same way, why are our physical bodies composed of certain atoms and chemical particles and so on? Again, there is no reason; it is simply its nature; it is simply the way it is. Then Buddha spoke of the law of dependence. This refers to phenomena that we normally posit in relation to something else, like parts and the whole, right and wrong, etc. And then there is the functional law — cause and effect. The function produces effects, and effects have the tendency to follow after their related causes.
All of this is quite close to scientific views; the subatomic physics theories come very near to explaining the natural law. It is also close to the Kalachakra Tantra explanation that space particles are the source, or origin, of all matter in the universe. And this natural law, on the subatomic level, is further expanded when there is interaction with different types of particles and so on. Then there is this second law — dependent law. And then, as a result of the interaction between various types of particles, different properties come into being; so this is quite similar to the third category — the functional law. By taking these three types of phenomena as the basis of analysis and logical examination, we use logical reasoning.
If we were to maintain that there must be a beginning at some point somewhere to consciousness, a big question mark would arise for us — how did that first moment of consciousness come about? Where did it come from? The only choice would be to accept that consciousness does not come from a cause at all. Another alternative, of course, would be to adhere to a belief in a creator.
As far as logic is concerned, therefore, one would conclude that consciousness is beginningless because consciousness requires an earlier moment of consciousness as its cause, and that moment of consciousness would, in turn, require an earlier instant of consciousness. Therefore, it is infinite and beginningless. This kind of explanation may not be a hundred percent satisfactory, but, still, it has less contradictions and inconsistencies within it than any other.
It is better to end this on a doubt!
[A question and answer given during a talk given by HH Dalai Lama in London, April 1988. From Buddhism Now Aug 1991]