Note (return) — Chapter VI

So that the assumption of final causes has not, as Bacon affirms, "led men astray" and "prejudiced further discovery;" on the contrary, it has had a large share in every discovery in anatomy and physiology, zoology and botany. The use of every organ has been discovered by starting from the assumption that it must have some use. The belief in a creative purpose led Harvey to discover the circulation of the blood. He says: "When I took notice that the valves in the veins of so many parts of the body were so placed that they gave a free passage to the blood towards the heart, but opposed the passage of the venal blood the contrary way, I was incited to imagine that so provident a cause as Nature has not placed so many valves without design, and no design seemed more probable than the circulation of the blood." 275 The wonderful discoveries in Zoology which have immortalized the name of Cuvier were made under the guidance of this principle. He proceeds on the supposition not only that animal forms have some plan, some purpose, but that they have an intelligible plan, a discoverable purpose. At the outset of his "Règne Animal" he says: "Zoology has a principle of reasoning which is peculiar to it, and which it employs to advantage on many occasions; that is, the principle of the conditions of existence, commonly called final causes." 276 The application of this principle enabled him to understand and arrange the structures of animals with astonishing clearness and completeness of order; and to restore the forms of extinct animals which are found in the rocks, in a manner which excited universal admiration, and has commanded universal assent. Indeed, as Professor Whewell remarks, at the conclusion of his "History of the Inductive Sciences," "those who have been discoverers in science have generally had minds, the disposition of which was to believe in an intelligent Maker of the universe, and that the scientific speculations which produced an opposite tendency were generally those which, though they might deal familiarly with known physical truths, and conjecture boldly with regard to unknown, do not add to the number of solid generalizations." 277