Dr. Tyndall begins by observing that "the idea of direct personal volition mixing itself in the economy of nature is retreating more and more" in presence of advancing science, and among educated and scientific communities there is a growing conviction that "nature is absolutely uniform," and that her laws are changeless and permanent. He takes the ground that all prayer for Divine interposition "to produce changes in external nature," such, for example, as "prayer for rain or for fair weather," is irrational, because the answer to such prayer would be "a violation of the order of nature," "a manifest contradiction to natural laws," and in fact "a _miracle_." "The dispersion of the slightest mist by the special volition of the Eternal would be as great a miracle ... as the stoppage of an eclipse or the rolling of the St. Lawrence up the Falls of Niagara. No act of humiliation, individual or national, could call one shower from heaven or deflect toward us a single beam of the sun."[436]
We have characterized this attack of Dr. Tyndall's as an attack on the efficacy of prayer from the _theoretical_ stand-point: 1. Because he does not claim that the belief in the changeless uniformity of nature is a _self-evident_ truth--a direct intuition, either of sense or of reason, which needs no proof. 2. Because he does not assert that the absolute uniformity of nature has been _inductively_ proved, or is even capable of verification by experience, since all experience, whether of the individual or the race, is necessarily limited, and can not, therefore, give a universal truth. All that he can say of it is that it is "an _assumption_"--an assumption which all carefully conducted experiments have justified, and upon which all successful scientific research has been based. The majestic fabric of modern science has been reared upon this foundation.
But mark, it is still "_an assumption_,"[437] and the central question around which the battle must be fought is, _What ground have we for the assumption that the order of nature is so absolutely persistent and changeless that it never has been and never can be interfered with by an act of intelligent volition?_
Dr. Tyndall has attempted an answer to this question. We shall endeavor, first, clearly to comprehend his answer, and, secondly, to estimate its logical validity.