||Skepticism involves doubt, or at least a reluctance to commit. For example, some philosophers are moral skeptics, claiming that no one can know what is right or wrong. Skepticism about the "external world" is more general, denying that there is knowledge of the world “outside our minds.” Even more generally, some skeptics claim that there is no knowledge at all. Philosophers have long explored reasons for and against various skeptical positions and argued about the consequences of adopting various skeptical stances. In the ancient world, skepticism was recommended as a way of life. The general claim was that living with an attitude of skeptical doubt is superior (morally and/or practically) to living with an attitude of dogmatic certainty. In the modern world (i.e., the 1600s through the 1800s), skepticism was more often treated as something to be avoided, and considerable philosophical energy was put into strategies for doing so. In contemporary philosophy, skepticism is typically framed as a theoretical problem rather than a practical one. The concern is to closely consider the best arguments for skepticism and to explore how best to respond to them. Attempts to answer skeptical arguments have inspired philosophers to adopt substantive positions in epistemology, but also in ontology, philosophy of mind, philosophy of language, and moral philosophy.