568 THE PLANT’S PLACE IN NATURE 
carried into the atmosphere of a planet, and without harm come to 
rest upon its surface there to germinate if the conditions proved to 
be favorable. It would thus appear that we have abundant scientific 
warrant for supposing that the first living things upon our earth were 
resting spores which came through vast spaces from some other 
planet; and that our simplest forms of life are being distributed sim- 
ilarly throughout the universe, just as similar living germs have been 
carried from planet to planet during endless ages for which it would 
be idle to seek a beginning. Life having always existed does not 
need to be accounted for in terms of physics and chemistry. 
If not in physical or chemical terms, how then can we 
define that which distinguishes all living from all lifeless 
things? Some naturalists have seemed to think that this 
question could best be answered by trying to interpret the 
more complex manifestations of life in the higher organisms 
through a study of the simpler manifestations of the lower 
forms: but this means trying to explain the life of which we 
know most by that of which we know least. A method 
just the reverse is surely more promising. When I ask myself 
what it is that makes me alive, my answer is: Not any par- 
ticular arrangement or movement of material particles of a 
certain sort, but rather an immaterial something which to 
some extent can control the arrangements and movements 
of such particles in accordance with purposes peculiarly my 
own. My body is alive only so long as it affords opportunity 
for the exercise of my will. It is my power of choice that 
makes me alive. What I choose gives me my character. My 
life and my individuality come from my power to choose 
and the way I use it. 
If you should ask me how I suppose an immaterial existence 
can exert an influence upon what is material, I must answer 
that I have no more idea than I have how mind can affect 
mind or matter affect matter. The real nature of either is 
doubtless very imperfectly expressed by any scientific defini- 
tions of them that were ever offered; but I donot need to know 
the ultimate truth about them in order to feel justified in be- 
lieving that somehow in every living creature the free will of 
something mental gets expressed through something material, 
1 For a fuller account of the theory of panspermia the student may 
profitably consult Worlds in the Making by Svante Arrhenius, 1908, 
from which the calculations given above have been taken. 
i 
