Columnist: Although much has been learned, we are still largely ignorant of the intricate interrelationships among species of living organisms. We should, ttherefore, try to preserve the maximum number of species if we have an interest in preserving any, since allowing species toward which we are indifferent to perish might undermine the viability of other species.
The principle 'We should always undertake the course of action that is likely to have the best consequences in the immediate future' most helps to justify the columnist's argument, if valid.