that the habit of this is conducive, not only to longevity, but to that prolonged youth of the mind which makes old age profitable. He had come to the conclusion that most of the revealing power born into the world is wasted for the service of mankind, by too early precipitating itself in some concrete form, or committing itself to some definite view or opinion. He said:—'The way to do good work is to live to be old. If you have genius, keep it fresh till you have experience as well.' He expressed to me certain conclusions to which he had come about the bad consequences, to the general morality and health, of the people being educated in habits of slavery to fixed mental attitude.
Gratry held that the Art of Thinking would never flourish during periods of intellectual individualism and competition; that the essential condition for any marked evolution of it is one of self-effacing communal study. This condition of generous selflessness prevailed in Mathematical Science during the great revival in which A. De Morgan and my husband took part, in the forties and fifties of the last century.
For the last thirty years there has existed an informal group of workers, organized on the communal plan suggested by Gratry, which
