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 that we should not allow a change to occur unless we are assured that that change will not jeopardize anything that is important to us most helps to justify the columnist's argument.