 Like Frege, Husserl ultimately seeks to refute psychologism by linking it closely to broader and (at the time) disreputable philosophical positions. But for Husserl the focus is less on subjective idealism and solipsism and more on skepticism and relativism. Husserl contends that all forms of psychologism are forms of ‘species relativism’, more precisely ‘anthropologism’. And he goes on to argue that such relativism is ‘absurd’. In order to get to this general conclusion, Husserl begins by arguing against Protagorean relativism. While acknowledging that the true Protagorean relativist can never be argued out of his position, Husserl holds that we ‘normally disposed’ people can nevertheless see what is wrong with the Protagorean viewpoint: the same sentence cannot be both true and false, and the Protagorean thesis, ‘truth is relative’, cannot itself be merely relatively true. (§35). Species relativism (and thus anthropologism) is equally absurd, but a little harder to refute. Husserl marshals a number of arguments against species relativism; the most important are (a) that since the Principle of Non-Contradiction is part of the meaning of truth, one and the same thought cannot be true for one species and false for another; (b) that truth are eternal and thus not temporally and spatially determined; and (c) that if truth were relative then so would be the existence of the world. This is because the world is the correlate of the ideal system of all factual truths. If truth were relative then there would be no such ideal system and thus no one unique world (§36). 