140 J.J. Haldane
species. In creating such a system God brought into being and sustains a
domain in which natural values are everywhere to be seen as organisms realize
their natures. The inevitable cost of this to others is also evident and consti-
tutes what we regard as natural evils.
Here two points of clarification are necessary. First, let me repeat that I am
not denying that bad things happen. When bacteria flourish at the expense of
an apple, or a cat at the cost of the life of a mouse, that really is bad for the
fruit and for the animal. Also, it is generally supposed that some gains and
losses are more important than others. On the view I am presenting this is
not a matter of subjective preference for the well-being of one thing over that
of another. In the system of interacting organisms there is a hierarchy of
substances, since living things can be ranked according to the character and
range of their natural powers. In the traditional Aristotelian scheme this
involves the three-fold classification described below.
Organism Powers
Rational Intellect – Will – Memory
Sentient Perception – Appetite – Locomotion
Vegetative Nutrition – Growth – Generation
Corresponding to each kind of living thing is a set of defining character-
istics – vital powers. What makes this a hierarchy, rather than a mere list, is
that types of organisms higher up the table have all the powers of those lower
down but not vice versa. Thus, like trees, rabbits take in material from their
environment, grow according to species-specific principles of development
and reproduce themselves; but they also perceive their environment, have
attractions and aversions towards aspects of it and move around within it.
Human beings share powers with both vegetative and sentient species but in
addition they are intellectual beings capable of rational thought and action.
Beings possessed of more and greater powers have open to them higher
forms of self-realization. By this very fact, however, they are vulnerable to
more and greater losses. In drought a tree may wither and die for want of
water, a rabbit may suffer the pain of dehydration, but in addition to under-
going these physical and sensory ordeals a human being may experience
despair at the end of her hopes for herself and her children. Those who have
more, have more to lose. The death of a human being thus constitutes a
greater loss than does that of a rabbit or a tree.
Notice, however, that by virtue of their speculative and practical reason
human beings have considerable abilities to avoid and recover from the injuri-
ous effects of nature, and more profoundly to discover how nature operates