According to classical utilitarianism, the only intrinsic good is happiness; the only intrinsic bad is pain. That implies no intrinsic value in preserving nature, that preserving an endangered plant is valuable only if it benefits humans or other animals. Intuitively, that seems wrong but perhaps I shouldn't trust my intuition here.
Peter SingerWe ought to consider the interests of animals because they have interests and it is unjustifiable to exclude them from the sphere of moral concern; to make this consideration depend on beneficial consequences for human beings is to accept the implication that the interests of animals do not warrant consideration for their own sakes.
Peter SingerI'm a Utilitarian, so I don't see the rule against lying as absolute; it's always subject to some overriding utility which may prevent its exercise.
Peter SingerIf we are concerned about the exploitation of human workers in countries with low standards of worker protection, we should also be concerned about the treatment of even more defenceless non-human animals.
Peter Singer