There are more ways of disturbing a well-functioning system, than of improving it to the same extent. Thus, arbitrary interferences with well-functioning systems are much more likely to damage them than to improve them. Furthermore, their order or degree of organization tends to decrease in the course of time because most changes in them will damage them. This is a part of what is known as entropy. If we remove any of the countless conditions, which are necessary to maintain the functioning of an integrated system, we shall interrupt its function, but in order to improve its function, we have to discover a condition which fits in so well with all these conditions that the function is enhanced.
This is the main reason why it is in general easier to kill than to save life. There are innumerable conditions which are necessary for an organism to continue to be alive . Thus, we could kill it by finding out which of these conditions is easiest for us to remove, and remove it. As there are many ways of killing an organism, there is likely to be some within our reach. By contrast, to save its life we have no choice but to restore something like the particular condition removed, however difficult that may be.
- Persson and Savulescu, Unfit for the Future: The Need for Moral Enhancement