I am intrigued that of all the hundreds of questions asked over the years, only two have been posed about euthanasia or voluntary suicide. Do we have the right to end our lives when we reach a rational decision to do so? On what basis do some people wish to deny us that right?

In order not to get bogged down in disputes about the nature of rights or the nature of rationality in general, let me rephrase your question as follows: If someone in sound mind decides to end his or her life, should this be allowed? If not, why not? One reason we might not allow a person of sound mind to commit suicide is that we think that person's decision is based on seriously incomplete or misleading evidence -- e.g. if her reading has led her to believe that her cancer is incurable when in fact it is quite easily eliminated. No matter how reasonable, and how well-read, a person is, it is possible to make bad decisions because one lacks good evidence. At the very least, we ought to intervene in such cases to make sure that the person has accurate information before acting. The very same evidence can lead different people to different conclusions, however, and we must not assume that everyone who disagrees with our own view (or an expert's view) is of unsound mind. Some people believe that a...