In scientific reasoning general rules are collected from the observation of many particular cases; and, when these general rules are established, conclusions are deduced from them, just as in everyday life. If a boy says that “marbles are hard,” he has drawn a conclusion as to marbles in general from the marbles he happens to have seen and felt, and has reasoned in that mode which is technically termed induction. If he declines to try to break a marble with his teeth, it is because he consciously or unconsciously performs the converse operation of deduction from the general rule “marbles are too hard to break with one’s teeth.”
You will learn more about the process of reasoning when you study logic, which treats of that subject in full. At present, it is sufficient to know that the laws of nature are the general rules respecting the behavior of natural objects, which have been collected from innumerable observations and experiments; or, in other words, that they are inductions from those observations and experiments. The practical and theoretical results of science are the products of deductive reasoning from these general rules.
Thus science and common sense are not opposed, as people sometimes fancy them to be, but science is perfected common sense. Scientific reasoning is simply very careful common reasoning, and common knowledge grows into scientific knowledge as it becomes more and more exact and complete.
The way to science then lies through common knowledge; we must extend that knowledge by common observation and experiment, and learn how to state the results of our investigations accurately, in general rules or laws of nature; finally, we must learn how to reason accurately from these rules, and thus arrive at rational explanations of natural phenomena, which may suffice for our guidance in life.
FOOTNOTES
[C] From Science Primers. Introductory. By Prof. T. H. Huxley, F.R.S.
THE CIRCLE OF THE SCIENCES.
Science means classified knowledge. There may be much general knowledge that is not science. It attains to that dignity only when the particular facts known are generalized, and arranged in some order, instead of being jumbled together, and lying about loosely in the memory, to be taken up at random. Especially must the basal facts of the science be verified, not assumed.