but the law may have been vaguely conceived, and, if absolutely necessary, 
it might have been roughly formulated, even though no one had ever thought of 
measuring the different energies of the physical world, even though the concept of
energy had not been created. essentially, it expresses the fact that all physical changes 
have a tendency to be degraded into heat, and that heat tends to be distributed among
bodies in a uniform manner. in this less precise form, it becomes independent of any
convention; it is the most metaphysical of the laws of physics since it points out without
interposed symbols, without artificial devices of measurements, the direction in which
the world is going. it tells us that changes that are visible and heterogeneous will be more and more diluted into changes that are invisible and homogeneous, and that the instability
to which we owe the richness and variety of the changes taking place in our solar system will gradually give way to the relative stability of elementary vibrations continually and perpetually repeated. just so with a man who keeps up his strength as he grows old, but
spends it less in actions, and comes, in the end, to employ it entirely in making his 
lungs breathe and his heart beat.  




-henri bergson