But Aristotle had overlooked something, or, being a practical man, perhaps overlooked it intentionally. The premise from which he deducted the watchfulness of dogs in general, was handed down by tradition and had been accepted on faith. But was it founded on fact? Could there not be some dogs who lacked the quality of watchfulness, and might not our pug-dog be very unreliable, in spite of all exact deductions? In the case of the pug-dog this would not be of very great moment. But what about the question of the beginning and end of the world, or the question of the existence of God? The Grecian gods had been outgrown by Aristotle. The history of logic, and of philosophy in general, is interrupted by Christianity and by the decline of the antique world, until the reformation opens a new era. The Catholic church had, in its own way, thoroughly settled the great questions of the true nature of things, of beginning and end, reason and consequence. But when it, and with it Christianity, began to disintegrate, disbelief once more posed in the brains of the philosophers the old question: How do we obtain reliable and true understanding? Reliability and truth were at that time still identical. Bacon and Descartes are the men who started the investigation. Both of them were disgusted with Aristotle and with his formal logic, particularly with the subtleties of scholasticism. It did not satisfy this new epoch to found positive understanding on traditional contentions and exact deductions therefrom. It is a radical epoch and, therefore, epoch-making. The new philosophers have the aim of unequivocal understanding in common with the ancient philosophers. Bacon still connects himself with the stock in trade of the past. His historian says of him that one should not reiterate that Bacon took his departure from experience, for this means nothing or nothing more than that Columbus was a mariner while the main thing is that he discovered America.... He wanted to find a new logic corresponding to the new life.... The inventive human mind has created the new time, the compass, the powder, the art of typography.... He wanted a new logic which corresponded to the spirit of invention. He, the philosopher of invention, was Lord Chancellor of England, was a man of the world. Not only himself, but also his science, was too ambitious, too full of energy, too world-embracing, for him to bury himself in solitude. That is a glory for a philosopher, but at the same time an obstacle for his special task, for the new logic. He recognized the import of his task only in its general outlines. But his contemporary and successor Descartes approached the matter more radically and pointedly.