ed solely from the point of view of material
causes, that is to say the cause of a pot is clay and not the action
of the potter. Thus the effect or product is nothing else than the
cause in another shape: production is only manifestation and
destruction is the resolution of a product into its cause. Instead of
holding like the Buddhists that there is no such thing as existence
but only becoming, the Sankhya rather affirms that there is nothing
but successive manifestations of real existence. If clay is made into
a pot and the pot is then broken and ground into clay again, the
essential fact is not that a pot has come into existence and
disappeared but that the clay continuously existing has undergone
certain changes.

The tendency to evolution inherent in matter is due to the three
_gunas_. They are _sattva_, explained as goodness and happiness;
_rajas_, as passion and movement; and _tamas_, as darkness, heaviness
and ignorance. The word Guna is not easy to translate, for it seems
to mean more than quality or mode and to signify the constituents of
matter. Hence one cannot help feeling that the whole theory is an
attempt to explain the unity and diversity of matter by a phrase, but
all Hinduism is permeated by this phrase and theory. When the three
gunas are in equilibrium then matter--Prakriti--is quiescent,
undifferentiated and unmanifested. But as soon as the equilibrium is
disturbed and one of the gunas becomes preponderant, then the process
of differentiation and manifestation begins. The disturbance of
equilibrium is due to the action of the individual Purushas or souls
on Prakriti, but this action is mechanical and due to proximity not
to the volition of the souls and may be compared to the attraction of
a magnet for iron.[744] Thus at the beginning of the evolutionary
process we have quiescent matter in equilibrium: over against this are
souls innumerable, equally quiescent but exerting on matter a
mechanical force. This upsets the equilibrium and creates a movement
which takes at first the form of development and later of decay and
collapse. Then matter returns to its quiescent state to be again
excited by the Purushas and commence its world-making evolution anew.
The doctrine that evolution, dissolution and quiescence succeed one
another periodically is an integral part of the Sankhya.[745]

The unmodified Prakriti stands first on the list of twenty-five
principles. When evolution begins it produces first Bu