It is commonplace to praise great ideas for having stood "the test of time." Implicit in that thought is that if an idea keeps kicking around, then it must capture some deep truth, a truth that allows it to resurface again and again in wildly different historical moments.
Francis Bacon thinks the opposite. On his view, the persistence of an idea is likely a symptom of its superficiality. It floats along the waters of time precisely because of its frivolity. Serious ideas are heavy and thus difficult to understand. So they sink down with time, rather than float along with the current.
From The Great Instauration:
"Now as far as the people are concerned, the doctrines that most flourish are either contentious and pugnacious, or bland and empty, such, that is, as either ensnare assent or win it by flattery. And therefore the greatest minds in every age have doubtless felt their force; while being men of uncommon capacity and understanding they have nonetheless, with an eye to their popular reputation, submitted to the judgement of time and of the multitude; and as a result, any more exalted reflections that may have gleamed forth were straightaway buffeted and extinguished by the winds of popular opinion. The result has been that Time, like a river, has brought down to us the light and inflated while it has sunk the weighty and solid." (Preface)
The pre-Socratics were better than Plato and Aristotle. They "did not open schools, so far as we know, but applied themselves to the search for truth more quietly, austerely and without fuss, making no great show or parade about their work. They did their work better, in my opinion, only their teachings have been obscured over the passage of time by those shallower men who pay more attention and regard to the grasp and wishes of common people. Time, like a river, brings down to us what is lighter and more puffed up, and lets the heavier, solid matters sink." (I.71)
Philosophy was corrupted after it became dominated by Plato and Aristotle. Things were fine until the fall of Rome, when Aristotelian and Platonic philosophy became dominant (I imagine he's blaming the Church for that): "It was only in still later times, with the flooding of the barbarians into the Roman Empires and the virtual shipwreck of human learning, that the philosophies of Aristotle and Plato, like light and insubstantial flotsam, survived the waves of time." (I.77)
