Choice of the term "reflection" to crystallize the remarks of the last chapter may or may not have been well advised. Yet the word "experience" can be taken as an obvious guiding line for an attempt to compress into one chapter some comments on the British empiricists of the late seventeenth and first half of the eighteenth century. This was the magic word that served as a final court of appeal and was itself given that immunity from questioning which each age accords to its key explanatory terms. "Let us then suppose the mind to be, as we say, white paper void of all characters, without any ideas. How comes it to be furnished?… To this I answer, in one word, from experience." ¹ "None but a fool or madman will ever pretend to dispute the authority of experience, or to reject that great guide of human life." ²