Whence, in fact, proceeds this general sway of prejudices; this might of the understanding in the midst of the light disseminated by philosophy and experience? The age is enlightened, that is to say, that knowledge, obtained and vulgarized, suffices to set right at least our practical principles. The spirit of free inquiry has dissipated the erroneous opinions which long barred the access to truth, and has undermined the ground on which fanaticism and deception had erected their throne. Reason has purified itself from the illusions of the senses and from a mendacious sophistry, and philosophy herself raises her voice and exhorts us to return to the bosom of nature, to which she had first made us unfaithful. Whence then is it that we remain still barbarians? There must be something in the spirit of man—as it is not in the objects themselves—which prevents us from receiving the truth, notwithstanding the brilliant light she diffuses, and from accepting her, whatever may be her strength for producing conviction. This something was perceived and expressed by an ancient sage in this very significant maxim: _sapere aude_.[1] Dare to be wise! A spirited courage is required to triumph over the impediments that the indolence of nature as well as the cowardice of the heart oppose to our instruction. It was not without reason that the ancient Mythos made Minerva issue fully armed from the head of Jupiter, for it is with warfare that this instruction commences. From its very outset it has to sustain a hard fight against the senses, which do not like to be roused from their easy slumber. The greater part of men are much too exhausted and enervated by their struggle with want to be able to engage in a new and severe contest with error. Satisfied if they themselves can escape from the hard labor of thought, they willingly abandon to others the guardianship of their thoughts. And if it happens that nobler necessities agitate their soul, they cling with a greedy faith to the formula that the state and the church hold in reserve for such cases. If these unhappy men deserve our compassion, those others deserve our just contempt, who, though set free from those necessities by more fortunate circumstances, yet willingly bend to their yoke. These latter persons prefer this twilight of obscure ideas, where the feelings have more intensity, and the imagination can at will create convenient chimeras, to the rays of truth which put to flight the pleasant illusions of their dreams. They have founded the whole structure of their happiness on these very illusions, which ought to be combated and dissipated by the light of knowledge, and they would think they were paying too dearly for a truth which begins by robbing them of all that has value in their sight. It would be necessary that they should be already sages to love wisdom: a truth that was felt at once by him to whom philosophy owes its name.[2]