Nebular Theory. — Mistotklcs. 22/ 
that errors may bo fouiul where we know beforehand that they 
exist. 
We gladly admit, however, that our sincere thanks are 
due the modern philosophers for so insistently recommending 
the study and application of the science of logic ; and for their 
telling us, that we can never gain a clear and comprehensive 
understanding of any subject except by means of logical 
thinking and harmonious and consistent reasoning. "Logic," 
says John Fiske. "is to the scientific investigator what the law 
of proof is to the lawyer." 
This is true, and it is, furthermore, of vital importance for 
our discussion of the theory in question. But logic alone is 
not sufficient. Let us, therefore, before we take up the prob- 
lems before us, add a few observations concerning certain 
rules, which every student of natural laws and forces must 
recognize and observe. 
However important and indispensable log:ic is to a scientific 
investigator, it can, nevertheless, serve only as & valuable as- 
sistant under certain conditions. As one of these conditions, 
may be mentioned a thorough and complete knowledge of the 
starting point from which one. by means of induction, seeks 
the solution of a problem. Xo matter how logically one may 
reason, if the first conclusion regarding the condition, essence 
or genesis of a thing is wrong, every subsequent conclusion, 
based on the first, will lead from error to error ad infinitum. 
It is the non-observance of this fact, as we shall show later, 
that has led the natural scientists to commit their greatest er- 
rors. They have been logical to the tips of their fingers, but, 
in many instances, totally blind as to the proper conditions for 
the use of logic. Thus we often find, that no distinction is 
made between a philosophical and a mathc^natical problem ; and 
we are told at times, that this or that scientist has solved 
mathematicallv a much discussed problem in spite of the fact 
that that same problem does not admit of a mathematical solu- 
tion. A philosophical problem cannot be solved by mathemat- 
ics ; for mathematics can give us a trustworthy result onlv 
when all the elements and parts of the subject are distin- 
guished and understood in all their details. The cubic contents 
of a hill and its elevation above the sea level, for instance, is 
a geometrical and, hence, a mathematical problem; but the 
