The Inductive Method--preserving the term Method to avoid confusion--in which the mode of procedure from Facts to Principles predominates, and which is hence sometimes called the Empirical, or the Experimental, or the Positive, or the _a posteriori_ Method, is that which now prevails in the world, which is extolled as if it were the only legitimate Method, and the only possible route to Scientific Discovery. That the just claims of the Inductive Method are very great is universally admitted, but let us not stultify ourselves by assuming a position in its defence which is in direct violation of the teachings of the Method itself,--namely, the assumption of a theory which is not verified by Facts. That the Inductive Method is vastly superior to the Anticipative or Hypothetical one, is abundantly proved; but that it is the _only_ correct path to Scientific truth, that it is the best path to Scientific truth which will ever be known, or that in a rightly balanced Method it would be the _main_ Process, is an averment for which there is no warrant. On the contrary, a very cursory examination of the Inductive Method will show defects which render it unavailable as the sole or the chief guide in Scientific inquiry. The leading characteristic of the Inductive Method, that for which it is mainly admired, is its cautious, laborious, oftentimes tedious Observation and Collection of the Facts of Experience, and their careful Classification as a basis for the derivation of a Principle or Law applicable to the Phenomena grouped together. By this means, it is said, we secure precision and _certainty_, by which is intended, not only the _certainty of that which is already observed and classified_, but also _the certainty of that which is deduced from the Law or Principle derived from these known Facts_. It is just here, however, that the Inductive Method is lacking. Experience may testify a thousand, ten thousand, any indefinite number of times, to the repetition of the same Phenomena, and yet we can have no _certainty_ of the recurrence of the same Phenomena, in the future, in the same way. All the Facts of Observation and Experience for thousands of years went to convince men that the earth was at rest and the sun and stars passing around it. A larger Experience showed them their error. How shall we know that our Observation has at any time included all the Facts necessary to establish a Law? The history of Science, even under the guidance of the Inductive Method, is a history of Principles announced as firmly established, which a little later were found to be defective and had to be adjusted to the advanced stage of human Experience. The very nature of the Inductive Method indicates its inadequacy for the largest and most important purposes of Science. It gives certainty, where it does give it, only up to the point of the present, _it can never afford complete certainty for the future_. The logical and rigid testimony of