THE PRESIDENT’S ADDRESS. 365 
great progress has been made because the scientific mind has become 
impressed with the necessity of, from time to time, examining every 
received theory, in order to ascertain whether it is still in accordance 
with facts. Thus, the phlogistic theory of chemistry promulgated 
by Stahl and Beccher was replaced by the oxygen theory of Lavoisier, 
when the discoveries of Scheele, Priestley, Cavendish and Black, showed 
it to be no longer tenable ; and in our own day a very considerable 
change in chemical theory and nomenclature has been made, because 
the facts were found not to agree with deductions from the received 
theory. Now, the Greeks did not neglect to observe facts, and in 
truth, all the theories that they formed were based on facts. But 
they had, as Buckle thinks the Scotch have, a strong bias towards 
deduction, and having once made a generalization, their tendency was 
to reason from it and accept the results of this reasoning without 
ascertaining whether they too were supported by the facts. From 
this, also, resulted a great indistinctness and haziness in their expla- 
nations of phenomena, even when they had by chance obtained some 
glimmering of the correct view. As in the case of the giant who 
received an accession of strength when he touched mother earth, it is 
for the advantage of all theorizers to come down frequently to the 
solid basis of reality. This tendency to deduction in the Greek mind 
had, indeed, its good side. To it we owe the geometry of Euclid, 
which is the logical exhibition of the conclusions implicitly contained 
in a few definitions, postulates, and axioms. [ln modern times there 
has been a close alliance between the mathematicians and the devo- 
tees of the sciences of observation and experiment, to their great 
mutual advantage. But whatever may have been the cause, the geo: 
metry of Euclid failed in ancient times specially to promote progress 
in other sciences. 
While the failure of the Greeks to make any great advance in 
this department has its lesson for us, the fact that they were the only 
race of antiquity that made great and persistent exertions to solve 
scientific problems has also its lesson. What was the cause of the great 
intellectual activity of this race? I believe it to have been due to 
the same causes that made the Greeks free, whether these were 
climatic, or racial, or connected with their occupation and mode of 
life. As compared with Rome or Carthage, Athens and some of the 
other great commercial cities of Greece were decidedly democratic, 
the Roman and Carthaginian populations having never been able to 
