LIMITS OF INVESTIGATION, 15 
mensurable with scientific truths, We will therefore 
abide by the words of Goethe; 
Whoso has art and science found, 
Religion, too, has he; 
Who has nor art nor science found, 
His should religion be.* 
And now, having provisionally averted uncalled-for 
objections and conflicts with ambiguous ideas, we may 
quietly consider the limits of natural science. Let us 
first pause at the address delivered with gencral approval 
by the physiologist Dubois-Reymond, at the fiftieth 
assembly of German Naturalists and Physicians. He 
made reference to a passage in the classical works of 
Laplace, in the Introduction to the Theory of Science, 
which we cannot refrain from quoting in full. The 
author of the “Mechanism of the Heavens,” says: “ Pre- 
sent events are connected with the events of the past by 
a link resting on the obvious principle that a thing cannot 
begin to exist without a cause which produces it. This 
maxim, known by the name of the Principle of Sufficient 
Cause, extends likewise to events with which it is not 
supposed to come in contact. Even the freest will can- 
not evoke them without a determining impulse.” “We 
must, therefore, regard the present condition of the uni- 
verse as the consequence of its former, and the cause 
of its future, condition. A mind, for a given moment 
acquainted with all the forces which animate Nature, 
and the reciprocal relations of the entities of which it is 
* Wer Wissenschafft und Kunst besitzt, 
Hat auch Religion ; 
Wer jene beiden nicht besitzt, 
Der habe Religion, 
