If we take the main portion from consciousness through existence (No 3 -10) as applying to the present life, the first two factors pertain to the past life, to the immediately preceding life, and the last two factors, birth, and ageing, and death, represent the next life, our future existence.

This division is made only as an expository device for giving a clear explanation of the working of the factors. We should not take these literally to mean that ignorance and volitional formations occurred only in the past and do not occur now or that birth and death are events that will take place only in the future. As we go along we will see that there is an interlocking of the factors, so that all of them can actually be found in each single existence.

Now let us take as our own starting point of explanation, the present existence in which we are living now. This starts with the third factor, consciousness. Our life is a stream of experience in which consciousness is the fundamental factor. Life begins at conception with a moment of consciousness and consciousness continues all the way through the course of one existence right up to the moment of death. Now the question comes up: What are the conditions that brought us into this present existence? From where does consciousness arise? Where have we come from? Have we come into being just by chance? Have we come into being through the will of some creator God? This is made clear through the teaching on dependent arising.