"This thoroughgoing scepticism is not what doubtless earnest zeal for truth and science fancies it has equipped itself with in order to be ready to deal with them — viz. the resolve, in science, not to deliver itself over to the thoughts of others on their mere authority, but to examine everything for itself, and only follow its own conviction, or, still better, to produce everything itself and hold only its own act for true. ... By the conversion of opinion held on authority into opinion held out of personal conviction, the content of what is held is not necessarily altered, and truth has not thereby taken the place of error. If we stick to a system of opinion and prejudice resting on the authority of others, or upon personal conviction, the one differs from the other merely in the conceit which animates the latter. Scepticism, directed to the whole compass of phenomenal consciousness, on the contrary, makes mind for the first time qualified to test what truth is; since it brings about a despair regarding what are called natural views, thoughts, and opinions, which it is matter of indifference to call personal or belonging to others, and with which the consciousness, that proceeds straight away to criticize and test, is still filled and hampered, thus being, as a matter of fact, incapable of what it wants to undertake."