When we do not know a person - and also when we do - we have to judge his size by the size and nature of his achievements, as compared with the achievements of others in his special line of business - there is no other way.
Necessity does everything well. In our condition of universal dependence, it seems heroic to let the petitioner be the judge of his necessity, and to give all that is asked, though at great inconvenience.
There is another way of disqualifying the metaphysicians.... Judge them by their works. What have they done for mankind beyond the spinning of airy fancies and the mistaking of their own shadows for gods?