Now understand that the conclusion of the above arguments is that firstly you should bear in mind the following rules: one person cannot be a specialist in a plethora of sciences; the same speech or words differ [when uttered by] two [different] people; [when uttered by] one they will be gold, and [when spoken by] the other they will be coal; the sciences result from the meeting of minds and are perfected with the passage of time; many matters that were theoretical in the past are now commonplace; to compare the past and present is a false comparison [the difference between them is too great]; due to their simplicity and candour, desert-dwellers cannot hide trickery and deception, as they may be concealed beneath the veil of civilization; many of the sciences result only from instilling customs in human nature and teaching it events and circumstances, when the time and environment are favourable; the light of man's vision cannot penetrate the future and he cannot perceive its particular circumstances; just as human life has a natural span which will come to an end, so too laws have a natural lifespan which comes to an end, of course; in terms of both time and place, the environment is vastly influential on people's circumstances; very many wonders of the past have become commonplace through the perfecting of means; human intelligence, even if exceptional, is not capable of creating a science and perfecting all at once; the science is rather like a child; [its development] is gradual.
Now that you have settled these matters in your head and can picture them, free yourself from the fancies of the present and the delusions of its environment, and plunge into the sea of time from the shore of this century. Then pass under the sea till you emerge at the Age of Bliss and behold the