66

O.62

fledgling bird to refuse to leave the nest and trust to its wings because it had read Babinet and thought aerostation impossible on hydrodynamical grounds.

For too many years Galileo's maxim, that we should prefer the simplest hypothesis, recommended itself to me only in the sense of the logically simplest, in spite of the fact that every new step in our understanding of Nature teaches us that phenomena are far more complex than we had supposed. But after I had come to see that I was getting led into incessant error, my mind was opened to the theory that the truly preferable hypothesis is, as Galileo himself conceived it to be, the one which is most facile and credible to the human mind and which our natural confidence recommends; and many tests in my own studies and those of others have confirmed me in this view. Consider the Daltonian theory, for example.