77. False Reasonings Properly So Called. -- I. Sophisms of Induction. -- Under this head are included all sophisms which arise in inductive reasoning, whether they affect the preliminaries (sophisms of observation) or the inductive reasoning itself (sophisms of interpretation, or of inductive inference).

(1) Sophisms of observation. -- Patient and honest observation is the starting-point of all inductive research. Too often, however, eagerness to reach a conclusion drives the investigator into assertions which go beyond the bounds of his observation:

(a) We see what we wish to see, instead of seeing what is. Example: Haeckel's primary monerons and Huxley's famous Bathybius.

(b) We do not see what we wish not to see. Example: The biological theories which would demonstrate the identity of the animal and the vegetable cell.

(2). Sophisms of interpretation. -- Those which consist in wrongly interpreting observed facts. The observation is complete, but the meaning attributed to it is added by a suggestion arising from the eagerness to form a complete system.

Example: To conclude from the fact that forms of energy may be expressed in terms of mechanical energy to the thesis that all corporeal energies -- including those developed in nervous tissue, and accompanied by sensation, passion, spontaneous movement, or by thought and volition -- are nothing but mechanical energies.

(3) Sophisms of inductive inference, or of induction. -- The example is illegitimately employed when we pass from one observed case to another without first taking care to connect both of them by means of induction with a natural cause. Ab uno disce omnes. The analogy is abused in the same way.^{1}

{1} Certain sophisms of induction may be classified indifferently in several of the groups of hasty generalizations.