EVOLUTION OF THE UNIVERSE. 609 
Sir Otrver Lopes, F.R.S. 
It is well known that a physical theory which ignores some of the 
elements of the problem is incomplete, and is therefore liable to break 
down when confronted with the facts. A physical theory cannot take 
the whole universe into account ; but if it is to be complete enough to be 
satisfactory and to make trustworthy predictions, it must take all relevant 
factors into account. 
Sir James Jeans began his discourse by saying that in this Section we 
were concerned only with the physical universe, that is with material 
bodies and the forces that act upon them. I suppose that is true. But 
the fact that it is true seems to make it impossible for this Section to enter 
upon a philosophical discussion of such a subject as the universe as a whole, 
and to decide its fate upon purely deterministic lines. For the universe 
certainly contains more than we deal with in this Section. We must 
remember that there are Sections D and K and I and J; that is, we 
must realise that the universe is not solely inorganic. Some of the matter 
is animated ; and although it is still obedient to the laws of physics and 
chemistry, an animated body behaves in a spontaneous manner not 
predictable by those laws. When a thing behaves as if it were alive, 
physics loses interest in it, and hands it over to another Section ; for it is 
incompetent to deal with motions attributable to spontaneity and free 
will. Live things are excluded from our instruments, and charwomen 
from our laboratories. Wherever life has entered in, the predictions of 
physicists and astronomers and mathematicians are liable to be spoilt. 
Laplace’s calculator might reckon the behaviour of every particle in the 
universe so long as it was not interfered with by life and mind. But purely 
physical evolution would. not anticipate or predict the occurrence of life 
and mind. 
I have looked sometimes at the ripples coming over the sand on a sea 
beach and leaving a deposit of foam. I have thought whether a mathe- 
matician, given sufficient data, could predict every ripple and every line 
of foam. Yes, he could, theoretically, provided there were no boats, nor 
any fish. The splash of a fish, the ripples of a boat, would put his 
calculations out. Given even a spark of free will, there are no data that 
can be supplied. It may be said that our sense of free will is an illusion. 
Well, that is a philosophical question that can be raised. But it cannot 
be settled in this Section. So I venture to think that before we can 
philosophise upon such a theme as the ultimate fate of the universe, we 
must be able to take everything into account, and philosophise with 
a very wide and comprehensive knowledge of reality. 
Maxwell showed how the effect of mind could be introduced into the 
scheme of physics without contravening any of the laws of energy, except 
the purely statistical second law of thermodynamics. His demon, by 
dealing with the particles individually and selectively directing them, 
could interfere with and neutralise the consequences supposed to be 
deduced from that law. I claim as a physicist that too much attention 
has been paid to this second law of thermodynamics, and that the final 
and inevitable increase of entropy to a maximum is a bugbear, an idol, 
to which philosophers need not bow the knee. 
1931 RR 
