High-tech scans are telling us ever more about how human brains function, yet such findings may never settle fundamental questions about the nature of consciousness and personal identity.
One famous debate on the subject was carried out through public letters written by Anthony Collins and Samuel Clarke between 1706 and 1708. Collins defended a materialist account, maintaining that the physical brain is the bearer of consciousness; Clarke argued that consciousness could not inhere in any material system.
“This public correspondence is one of the most important works about the nature and role of consciousness and the nature of personal identity in the debate between materialists and dualists, in the eighteenth century,” said William Uzgalis, a Research Fellow and professor of philosophy at OSU. “It also deals with a number of other issues, the most important of which is free will and deter-minism.”
Because there is no modern, complete text of the corres-pondence, readers must turn to the 1738 edition of Clarke’s works, with the original antique typography and grammar. Uzgalis has set out to remedy this by producing an edited volume that will include the letters plus an introduction to provide historical context, and a summar-ization of the main arguments that will eliminate long quotes from the men’s own previous letters “to show the reader what they had really said.”
The debate began with a letter by Clarke to scholar Henry Dodwell, who contended that the Bible supports the claim that the soul is naturally mortal. Clarke objected, arguing that, for the soul to be naturally mortal, conscious-ness would have to belong to a material system such as the brain. He went on to argue that this is not possible, that consciousness cannot belong to any material system.
Collins wrote to Dodwell in turn, contending that Clarke’s argument was inconclusive, that life and consciousness emerge from matter that is properly organized and that, as a consequence, it could go out of existence when its material organization was destroyed. He also argued that persons, like other animals in nature, are determined and have no free will.
Clarke then wrote four defenses of his argument, and Collins wrote three replies to Clarke’s defenses. The entire correspondence takes up 205 pages in Clarke’s Works.
“Clarke and Collins argue about whether consciousness is such that it requires mind-body dualism or whether it could simply emerge from the organization of the brain. Similarly, they debate the nature of personal identity. Is it consciousness that determines personal identity, as John Locke had argued, or does personal identity require sameness of substance, as Locke’s critics claimed? Finally, Collins claims that human beings are determined in their actions while Clarke argues for free will.”
In attacking Collins’s account of personal identity, Clarke argues that, if persons are a collection of properties rather than a substance, then God could exactly reproduce any collection of properties and so could make two, or twenty, or a thousand copies of the same person. This, however, “violates our intu-itions that personal identity is a one-one relationship.”
Despite both its intrinsic interest and historical importance, Uzgalis said, the Clarke/Collins corre-spondence has been much neglected. Similar debates in the mid-twentieth century have recapit-ulated many of the same arguments.
“It was only several decades later that philosophers realized that these arguments were first given at the beginning of the eighteenth century and not in the early 1950s. . . Similarly, Collins’s defense and Clarke’s rejection of a materialist account of consciousness, and Collins’s attempt to produce an account of emergent properties, has important echoes in the debates over whether computers can think. There is considerable discussion about emergent properties in the literature on artificial intelligence, and seeing what that debate looked like when our understanding of matter, and particularly living matter, was much more impov-erished than presently is both interesting and informative.”