The fundamental explanation of the difference in the mental life of two groups is not that the capacity of the brain to do work is different, but that the attention is not in the two cases stimulated and engaged along the same lines.  Wherever society furnishes copies and stimulations of a certain kind, a body of knowledge and a technique, practically all its members are able to work on the plan and scale in vogue there, and members of an alien race who become acquainted in a real sense with the system can work under it.  But when society does not furnish the stimulations, or when it has preconceptions which tend to inhibit the run of attention in given lines, then the individual shows no intelligence in these lines.  This may be illustrated in the fields of scientific and artistic interest.  Among the Hebrews a religious inhibition—­“thou shalt not make unto thee any graven image”—­was sufficient to prevent anything like the sculpture of the Greeks; and the doctrine of the resurrection of the body in the early Christian church, and the teaching that man was made in the image of God, formed an almost insuperable obstacle to the study of human anatomy.

The Mohammedan attitude toward scientific interest is represented by the following extracts from a letter from an oriental official to a western inquirer, printed by Sir Austen Henry Layard: 

    My Illustrious Friend and Joy of my Liver:

The thing which you ask of me is both difficult and useless.  Although I have passed all my days in this place, I have neither counted the houses nor inquired into the number of the inhabitants; and as to what one person loads on his mules and the other stows away in the bottom of his ship, that is no business of mine.  But above all, as to the previous history of this city, God only knows the amount of dirt and confusion that the infidels may have eaten before the coming of the sword of Islam.  It were unprofitable for us to inquire into it....  Listen, O my son!  There is no wisdom equal to the belief in God!  He created the world, and shall we liken ourselves unto him in seeking to penetrate into the mysteries of his creation?  Shall we say, Behold this star spinneth round that star, and this other star with a tail goeth and cometh in so many years?  Let it go!  He from whose hand it came will guide and direct it....  Thou art learned in the things I care not for, and as for that which thou hast seen, I spit upon it.  Will much knowledge create thee a double belly, or wilt thou seek paradise with thine eyes?...

The meek in spirit, IMAUM ALI ZADI.[264]

The works of Sir Henry Maine, who gained by his long residence in India a profound insight into the oriental character, frequently point out that the eastern pride in conservatisms is quite as real as the western pride in progress: