The following procedure seems epistemically defective. Suppose I have no reason to think the gas gauge in my car is reliable, and I attempt to establish its reliability as follows. I read the gauge on many occasions, concluding each time that the tank is as the gauge says; when the gauge reads ‘full’, I conclude that the tank is full, similarly for ‘empty’, etc. Eventually I conclude by induction that the gauge is reliable, since it was correct each time. Even if my beliefs in this chain of reasoning are all true, I have done nothing to establish that the gauge is reliable: I do not know that it is reliable, nor am I justified in believing that it is. Call this sort of defective procedurebootstrapping.1 Our topic here is: what is defective about this sort of reasoning, and what epistemological lessons can we learn from its defectiveness? Vogel (2000) argues that bootstrapping presents a problem for reliabilist theories of knowledge. According to Vogel, reliabilism says that I can use the reasoning just outlined to come to know that my gauge is reliable. Cohen (2002; 2005), Van Cleve (2003), and others argue that bootstrapping actually poses a more general problem, afflicting any view that allows for basic knowledge, i.e. any view that allows one to gain knowledge from a source without prior knowledge that the source is reliable.2 Thus bootstrapping is also a problem for foundationalists who allow one to gain knowledge from perception without prior knowledge that perception is reliable.