A seminal passage from Freud's "Beyond the Pleasure Principle"

"...Those instincts are therefore bound to give a deceptive appearance of being forces tending towards change and progress, whilst in fact they are merely seeking to reach an ancient goal by paths alike old and new. Moreover it is possible to specify this final goal of all organic striving. It would be in contradiction to the conservative nature of the instincts if the goal of life were a state of things which had never yet been attained. On the contrary, it must be an OLD state of things, an initial state from which the living entity has at one time or other departed and to which it is striving to return by circuitous paths along which its development leads. If we are to take it as a truth that knows no exception that everything living dies for INTERNAL reasons- becomes inorganic once again- then we shall be compelled to say that 'THE AIM OF ALL LIFE IS DEATH' and, looking backwards, that 'INANIMATE THINGS EXISTED BEFORE LIVING ONES.'"