There was no resisting such firmness. I pointed with my finger to a corner in the kitchen, where stood a chair with no seat to it and, on that chair, a demijohn containing two or three gallons. “That’s my cellar, sir.” “Is that your cellar?” “I have no other.” “Is that all?” “Yes, that’s all, I’m sorry to say.” “Really!” Not a word more; nothing further from the savant. Pasteur, it was evident, had never tasted the highly-spiced dish which the vulgar call la vache enragée. Though my cellar—the dilapidated chair and the more than half-empty demijohn—had nothing to tell of the fermentation to be checked by heat, it spoke eloquently of another thing which my illustrious visitor seemed not to understand. There was one microbe that escaped his notice, and a very terrible microbe: that of ill-fortune strangling good-will. In spite of the unlucky introduction of the cellar, I am none the less struck by his serene assurance. He knows nothing of the transformation of insects; he has just seen a cocoon for the first time and learnt that there is something inside that cocoon, the rough draft of the moth that will be; he is ignorant of what is known to the meanest schoolboy of our southern province; and this novice, whose artless questions surprise me so greatly, is about to revolutionize the hygiene of the Silk-worm nurseries. In the same way, he will revolutionize medicine and general hygiene. His weapon is theory, heedless of details, and taking a bird’s-eye view of the whole question. What cares he for metamorphoses, larvæ, nymphs, cocoons, pupæ, chrysalids and the thousand and one little secrets of entomology! For the purposes of his problem, perhaps, it is just as well to be ignorant of all that. His theories will retain their independence and their daring flight all the more easily; their movements will be all the freer, when released from the leading-strings of the known. Encouraged by the magnificent example of the cocoons rattling in Pasteur’s astonished ears, I have made it a rule to adopt the method of ignorance in my investigations of the instincts. I read very little. Instead of turning the pages of books, an expensive proceeding quite beyond my means, instead of consulting other people, I persist in obstinately interviewing my subject until I succeed in making him speak. I know nothing. So much the better: my queries will be all the freer, now in this direction, now in the opposite, according to the glimpses of light obtained. And if, by chance, I do open a book, I take care to leave a compartment of my mind wide open to doubt; for the soil which I am clearing bristles with weeds and brambles.