The characteristic of this Method is the precise Observation of Facts or Phenomena and the Induction (drawing in) or accumulation of these accurate Observations as the basis of knowledge. (This is seemingly the first or etymological reason for the use of the term _Induction_; a term subsequently transferred, as we shall see, to the establishment of the Laws, from which then _ulterior_ Facts are to be _deduced_.) When a sufficient number of Facts have been accumulated and classified in any sphere of investigation, and these are found uniformly to reveal the same Law or Principle, it is assumed that all similar Phenomena are invariably governed by this Principle or Law, which, in reality _deduced_ or derived, is, by this inversion of terms, said to be _induced_ from the observed Facts. The Law so established has thenceforth two distinct functions: I, all the Facts of subsequent Observation, by the primitive Method of observation, are ranged under the Law which, to this extent, serves merely as a superior mode of classification; and, II, the Law itself, now assumed to be known and infallible, becomes an instrument of prevision and the consequent discovery through it of new Facts, the same which were meant by the expression 'ulterior Facts' above used. It is this _deduction_ of new Facts from an established Law which constitutes the true and legitimate Deductive Method of Science, the third of the three Methods above stated and the one which, as has been pointed out, is often erroneously confounded with the Anticipative or Hypothetical Method. The mode of investigation by the Inductive Method is, therefore, in general, similar to that which Aristotle and the Greek Scientists adopted. It first Observes and Collects Facts; then it resorts to Classification for the purpose of discovering the Law by which the observed Facts are regulated; then _derives_ from this Classification a General Law, presumed to be applicable to all similar Facts, although they have not yet been observed; and, finally, _deduces_ from the General Law thus established, new Facts and Particulars, by bringing them in under the Law.