If you present your dog to a veterinarian with the instruction to put him to sleep, you would normally mean something very different than you would upon taking your wife or husband to an anesthesiologist with the same words.
The subject of death is taboo. We feel, perhaps only subconsciously, that to be in contact with death in any way, even indirectly, somehow confronts us with the prospect of our own deaths, draws our own deaths closer and makes them more real and thinkable.
Dying, we tell ourselves, is like going to sleep. This figure of speech occurs very commonly in everyday thought and language, as well as in the literature of many cultures and many ages. It was apparently quite common even in the time of the ancient Greeks.
