8o The Course of Nature. [January, 
seeks nor avoids the crevices, never asks in any way what 
shall be its destiny after it reaches the ground. It strikes 
the ground wherever gravity and the winds bring it, per- 
colates through the soil according to the law of least 
resistance, and dissolves the rock according to the laws of 
chemical affinity, without any respect to the consequences, 
immediate or remote. At length a moment arrives at which 
the cohesive force of the rock becomes less than the weight 
which urges it downward. This moment is fixed entirely 
by antecedent circumstance, such as the solubility of the 
rock, and the amount of water which percolates over it. 
At this very moment the rock begins to fall. It falls six- 
teen feet the first second, three times that distance the 
next, and so on, according to the mathematical law of falling 
bodies, without any respeft to the lovely character of the 
beings it may destroy, or the disasters with which it may 
crush the fondest hopes of men. The region may be the 
wilderness ; the passer-by may be a babe in its nurse’s arms, 
an angel of charity, fulfilling her mission of good will, or a 
murderer aiming the deadly blow at his vicftim ; hut under 
no circumstances can we see that these conditions in any 
way affedl the chain of causes which lead to .the falling of 
the rock, or cause it to wait a moment, or swerve a hair’s 
breadth from its inevitable course. 
According to the theory of the course of nature, which I 
am trying to elucidate, the chain of causes which we have 
described, each cause adting according to antecedent con- 
ditions, but without any regard to consequences, is the type 
of the whole course of inanimate nature, as far in space as 
the telescope can penetrate, and as far back in time as the 
geological record can be deciphered. An essential feature 
of the theory is, that the laws which connect the several 
links of the chain, and thus determine the progress of events , 
do not possess that character of inscrutability which belongs 
to the decrees of Providence, but are capable, so far as 
their sensible manifestations are concerned, of being com- 
pletely grasped by the human intellect, and expressed in 
scientific language. Without this the theory would have 
no practical bearing whatever ; because, to say that the 
course of events is fixed, but by laws which we can never 
grasp, would give us no clue at all to learning what that 
course shall be, and would be equivalent to telling us that it 
is enshrouded in the same impenetrable mystery with first 
causes. A very important feature of the progress of science 
is found in the constant resolution of the laws of nature into 
more simple and elementary ones, until we reach principles 
