Richard Dees

: The idea of enhancing our mental functions through medical means makes many people uncomfortable. People have a vague feeling that altering our brains tinkers with the core of our personalities and the core of ourselves. It changes who we are, and doing so seems wrong, even if the exact reasons for the unease are difficult to define. Many of the standard arguments against neuroenhancements—that they are unsafe, that they violate the distinction between therapy and enhancements, that they undermine equality, and that they will be used coercively—fail to show why the use of any such technologies is wrong in principle. Two other objections—the arguments that such changes undermine our integrity and that they prevent us from living authentic lives—will condemn only a few of the uses that are proposed. The result is that very few uses of these drugs are morally suspect and that most uses are morally permissible.

David Hume is an ardent supporter of the practice of religions toleration. For Hume, toleration forms part of the background that makes progress in philosophy possible, and it accounts for the superiority of philosophical thought in England in the eighteenth century. As he puts it in the introduction to the Treatise: “the improvements in reason and philosophy can only be owing to a land of toleration and of liberty” (T Intro.7; SBN xvii).1 Similarly, the narrator of part 11 of the First Enquiry comments: Our conversation began with my admiring the singular good fortune of philosophy, which, as it requires entire liberty above all other privileges, and chiefly flourishes from the free opposition of sentiments and argu­ mentation, received its first birth in an age and country of freedom and toleration. (EHU 11.2; SBN 132) The toleration to which Hume refers is broader than religious toleration, but in the context of the eighteenth century, religious toleration is clearly the paradigm case. Indeed, religious toleration represents one of the key accomplishments of the culminating event of Hume’s History of England: the Glorious Revolution of 1688. Yet even though religious toleration forms the background of philosophy in general—or perhaps just because it does so—Hume offers precious few arguments for it, and they are, for the most part, given implicitly rather than as formal argu­ ments. Nevertheless, we can distinguish three different, though interrelated, lines of support for toleration in Hume’s thought: (i) an argument based on a general skepticism; (ii) an argument based on a contempt for organized religion; and (iii) a pragmatic argument based on the need for peace and orderly government. From our point of view, what is striking about all of these argument is how un-Lockean they are: Hume does not rely on the idea of a fundamental conceptual separation of church and state, nor on a natural right to freedom of conscience that character­izes writers working in the Lockean tradition. However, of the arguments he gives, only the last, I will argue, has any hope to provide a useful case for toleration.