 Whilst none of (P1), (P2), and (P3) is incontestable, nor is any one of them easily contested. Save perhaps for far-reaching metaphysical reasons (e.g., an antecedent commitment to idealism), few would deny the very existence of animals, nor the fact that a perfectly good specimen of the species Homo sapiens is presently seated in your chair. So (P1) is not easily rejected.