Two protechnology arguments, the “hopeful principle” and the “automatic escalator”, often used in bioethics, are identified and critically analysed in this paper. It is shown that the hopeful principle is closely related to the problematic precautionary principle, and the automatic escalator argument has close affinities to the often criticised empirical slippery slope argument. The hopeful principle is shown to be really hopeless as an argument, and automatic escalator arguments often lead nowhere when critically analysed. These arguments should therefore only be (...) used with great caution. (shrink)