The impact of human activities on the biosphere has accelerated rapidly during the last 200 years, and particularly so since the second half of the 20^th century consequent upon an exponential rate of population growth combined with scientific and technological developments. Advances in technology continue to facilitate the exploitation of the world’s organic resources and the manipulation of its physical environment. This has called for increased efforts towards the conservation of the world’s biodiversity so as to reduce the rapid rate of species extinction and decline. This review paper explores the arguments and counter-arguments that have been put forward for the conservation of biological diversity. The ultimate purpose of the review is to broaden the horizon on the value of biodiversity, which will help in diminishing the narrow, humanistic valuation of biodiversity largely responsible for the current biodiversity crisis. Indeed, one of the causes of the accelerated loss of biodiversity has been the utilitarian and human-centred argument that has largely been put forward as justification for the conservation of the world’s biodiversity. The major weakness with a conservation system based on economic motives is that most members of the biological community do not have immediate economic value. Therefore, justifying species preservation for utilitarian purposes predisposes many seemingly useless species to extinction. Only a moral or ethical argument for the conservation of biodiversity in which nature is conserved for its own sake, combined with sustainable use, can ensure a more effective conservation of the world’s organic resources.