Reading guide for Thurs. 12/3: Ruse, “Biological Species: Natural Kinds, Individuals, or What?” (on JSTOR)
After physics, biology is probably the science that has attracted the most interest of philosophers of science. Ruse addresses one of the standard questions in the philosophy of biology, the nature of “the species concept.”
Ruse outlines a number of theories about this before settling on the one he advocates. He is pretty good about presenting arguments on all sides. You should think what seems to you to be the strongest argument for and the strongest argument against each of these views.
Ruse naturally does the most to present and defend the view he agrees with. You should ask yourself what you think proponents of other views would say in response to his arguments.
The idea of “consilience of induction” is in fact due to the philosopher and historian of science William Whewell (1794-1866), who Ruse mentions in the next paragraph. Here is Whewell’s own introduction to the idea:
We have here spoken of the prediction of facts of the same kind as those from which our rule was collected. But the evidence in favour of our induction is of a much higher and more forcible character when it enables us to explain and determine cases of a kind different from those which were contemplated in the formation of our hypothesis. The instances in which this has occurred, indeed, impress us with a conviction that the truth of our hypothesis is certain. No accident could give rise to such an extraordinary coincidence. No false supposition could, after being adjusted to one class of phenomena, exactly represent a different class, when the agreement was unforeseen and uncontemplated. That rules springing from remote and unconnected quarters should thus leap to the same point, can only arise from that being the point where truth resides.
Accordingly the cases in which inductions from classes of facts altogether different have thus jumped together, belong only to the best established theories which the history of science contains. And as I shall have occasion to refer, to this peculiar feature in their evidence, I will take the liberty, of describing it by a particular phrase; and will term it the Consilience of Inductions.
It is exemplified principally in some of the greatest discoveries. Thus it was found by Newton that the doctrine of the Attraction of the Sun varying according to the Inverse Square of this distance, which explained Kepler's Third Law of the proportionality of the cubes of the distances to the squares of the periodic times of the planets, explained also his First and Second Laws of the elliptical motion of each planet; although no connexion of these laws had been visible before.…
William Whewell, Philosophy of the Inductive Sciences, 2nd ed. (London, 1847), vol. 2, pp. 65f.)