changeable there is bound to be confusion. You cannot project a cinema picture on a
screen which itself is changing constantly.
Another point to note is that the Purusa should not only provide a constant
background for the modifications of the mind but that his consciousness should be the
ultimate background in order that he may be able to notice modifications in the mind
at all its levels. When the Yogi passes into Samadhi and dives into the deeper levels of
the mind he is not conscious of any break in his experiences. The new consciousness
which emerges at each level seems to take in, understand and co-ordinate experiences
of all the previous stages and, therefore, there must really be the same consciousness
illuminating the Citta at all these different levels. It is not only our ordinary experi-
ences at the level of the concrete mind of which this ultimate consciousness is con-
stantly aware but also all the supramental experiences through which the Yogi passes
in Samadhi.
The extraordinary comprehensiveness which characterizes consciousness of the
Purusa in the ultimate background, is, of course, due to the fact that it is eternal, be-
yond time and space, and contains simultaneously within itself everything that can
ever manifest in the realms of time and space. It is only white light which is a harmo-
nious synthesis of all possible colours which can be used in the projection of a col-
oured film on a cinematographic screen. Coloured light which is incomplete cannot be
used for such a purpose.
- Nor is it self-illuminative, for it is perceptible.
After stating in IV-18 that the Purusa is the sole eternal witness of all modifica-
tions in the mind at whatever level they may take place, Patanjali proceeds to substan-
tiate this statement by a chain of reasoning developed in the next four Sutras.
The first link in this chain is that the mind is not self-illuminative, i.e. capable
of perceiving by its own power, because it is itself perceptible. It is not like the Sun