we may surmise that they began by by being implied
in each other, that the original psychical activity
included both at once, and that, if we went far enough
back into the past, we should find instincts more nearly 
approaching intelligence than those of our insects, 
intelligence nearer to instinct than that of our vertebrates,
intelligence and instinct being, in this elementary condition,
prisoners of a matter which they are not yet able to control.
if the force immanent in life were an unlimited force,
it might perhaps have developed instinct and intelligence together,
and to any extent, in the same organisms. but everything seems
to indicate that this force is limited, and that it soon exhausts itself
in its very manifestation.


henri bergson's creative evolution,
intelligence and instinct.