Blanchard claims "that Darwinian biology allows an understanding of the human species that is plenty robust enough to support the natural rights principles of the Declaration; that Darwinian biology is neither metaphysically nor morally reductionist; and that Darwinian biological science in fact provides powerful support for precisely the view of human nature upon which the Declaration rests" (2).
Blanchard sees two general reasons why Darwinian biology might be understood as denying the Declaration of Independence. The first is that in affirming that all human beings are morally equal in being created equal as endowed by their Creator with rights, the Declaration seems to require a sharp metaphysical and moral distinction between the human species and all other species that makes human beings unique; but Darwinian biology seems to deny such sharp distinctions between species and to claim that human beings differ only in degree and not in kind from closely related species.
The second problem is that in appealing to "the laws of Nature and of Nature's God," "the Supreme Judge of the world," "divine Providence," and "sacred honor," the Declaration points to the moral beauty of human life in looking to the noble and the divine; but Darwinian biology seems to deny such moral beauty in its reductionist view of all human motivations as ultimately directed only to survival and reproduction in serving their "selfish genes."
To recognize all human beings as morally equal and morally elevated, we must be able to recognize all human beings as human, as belonging to the same human species, as distinct from other species; and we must be able to recognize a moral capacity as one of the unique traits of the human species. Blanchard argues--correctly, I think--that modern Darwinian biology allows us to do that. But I disagree with his suggestion that Darwin would not support this.
Early in his paper, Blanchard refers to Darwin's Origin of Species and then indicates that he will separate Darwinian biology from Darwin: "I will use the Darwinian terms to indicate the present state of the theory and not its state when Darwin sent the manuscript to his London publishers" (9). Then, later in his paper, he observes: "If defenders of the Declaration had spent a little less time reading the admittedly seminal works of a Victorian Englishman and a lot more time reading works of contemporary evolutionary anthropology and psychology, they might have realized that . . . Darwinian biology confirms the account of human nature presented in the Declaration" (36).
Of course, Blanchard is right that contemporary evolutionary science has advanced far beyond Darwin and has corrected some of Darwin's mistakes. Nevertheless, I am impressed by the extent to which modern evolutionary science confirms and deepens the ideas first developed by Darwin; and this is true for all of the points where Blanchard sees modern biology sustaining the reasoning of the Declaration of Independence. Even if this seems like a minor issue, it should be important for a panel on "Darwin and the Declaration of Independence."
Consider the concept of species. The Declaration of Independence seems to assume that we can recognize the equal humanity of human beings as belonging to the same species. But there is an old debate among biologists and philosophers as to whether the classification of living beings into species conforms to a natural reality or is rather a purely arbitrary convention of names. The essentialists have claimed that the classification of species manifests an eternally fixed order of nature, so that each species has an essence defined by some necessary and sufficient traits that belong to all members of that species, and thus there are clear boundaries in nature separating each species from all others. By contrast, the nominalists have claimed that species have no real existence except as names invented by the human mind to organize the chaotic flux of sense experience. If the nominalists are right, then the Declaration of Independence is wrong to assume that human beings can be truly identified as equal in their membership in the human species.
If the Declaration must assume an essentialist conception of species, that surely creates a conflict with evolutionary biology, which must deny the essentialism of eternally fixed species, because then the evolutionary transformation of species would be impossible. And as Blanchard indicates, Darwin rejected the essentialist view of species. But, then, by embracing nominalism, Blanchard argues, Darwin subverted the thinking of the Declaration of Independence.
Darwin seems to show his nominalism in this passage from The Origin of Species quoted by Blanchard:
"I look at the term species as one arbitrarily given, for the sake of convenience, to a set of individuals closely resembling each other, and that it does not essentially differ from the term variety, which is given to less distinct and more fluctuating forms. The term variety, which is given to less distinct and more fluctuating forms. The term variety, again, in comparison with mere individual differences, is also applied arbitrarily, for convenience sake" (1859, 52; 1936, 46).And yet despite the impression conveyed by this passage, Darwin did not deny the natural reality of species. In fact, he thought he provided the best biological explanation of the natural basis for classifying species, which is neither strictly essentialist nor strictly nominalist. He insisted that "the characters which naturalists consider as showing true affinity between any two or more species, are those which have been inherited from a common parent." Therefore, "community of descent is the hidden bond which naturalists have been unconsciously seeking, and no some unknown plan of creation, or the enunciation of general propositions, and the mere putting together and separating objects more or less alike." All true classification, he insisted, "must be strictly genealogical in order to be natural." A "natural system" of classification must be based on natural affinities of organisms as they are related by phylogenetic descent (1859, 420; 1936, 323).
Harvard biologist Louis Agassiz was one of the leading critics of Darwin's theory of evolution when Darwin proposed it in 1859. As a Christian Platonist, Agassiz regarded species as thoughts in the mind of God and therefore fixed essences that could not have evolved through any historical process. For Agassiz, Darwin's denial of the eternal fixity of species was a denial of the very reality of species.
Agassiz wrote: "If species do not exist at all, as the supporters of the transmutation theory maintain, how can they vary? And if individuals alone exist, how can differences which may be observed among them prove the variability of species?" In a letter to Asa Gray in 1860, Darwin responded: "How absurd that logical quibble 'if species do not exist, how can they vary?' As if anyone doubted their temporary existence?"