The Nature of Scepticism

In practice, I would say yes. The first and most important skeptic is the scientist proposing the theory. The research that they have done to support their conclusion is a methodical application of skepticism. The null hypothesis is a distillation of skepticism. One way of constructing the null hypothesis is to think of the criticisms that a skeptic would use against your experiments, such as the oft cited placebo effect seen in drug trials.