Page:Biographia literaria; or, Biographical sketches of my literary life and opinions (IA biographialitera04cole).pdf/267

 separation and exclusion of those, which appertain to the opposite science. As the natural philosopher, who directs his views to the objective, avoids above all things the intermixture of the subjective in his knowledge, as for instance, arbitrary suppositions or rather suffictions, occult qualities, spiritual agents, and the substitution of final for efficient causes; so on the other hand, the transcendental or intelligential philosopher is equally anxious to preclude all interpolation of the objective into the subjective principles of his science, as for instance the assumption of impresses or configurations in the brain, correspondent to miniature pictures on the retina painted by rays of light from supposed originals, which are not the immediate and real objects of vision, but deductions from it for the purposes of explanation. This purification of the mind is effected by an absolute and scientific scepticism to which the mind voluntary determines itself for the specific purpose of future certainty. Des Cartes who (in his meditations) himself first, at least of the moderns, gave a beautiful example of this voluntary doubt, this self-determined indetermination, happily expresses its utter difference from the scepticism of vanity or irreligion: Nec tamen in eo scepticos imitabar, qui dubitant tantum ut dubitent, et preter incerti tudinem ipsam nihil quærunt. Nam contra