I reply, it is a truth reached by previous induction. Every deduction implies previous induction. I observe the mortality of individuals, _x_, _y_, _z_. I find no exceptions. My observation extends to a great number of cases, insomuch that I am authorized to take those cases as fairly representing the whole class to which they belong. I conclude, therefore, that what I have observed of the many is true of the whole. So comes the general proposition, All men are mortal. _Authority for this Belief._--But what reason have I to believe that what is true of the many is true of the whole, and how do I know this? I reply, I do not know it by observation, nor by demonstration; my belief of it rests upon, and resolves itself into, that general law or constitution of the mind according to which I am led to expect, under like circumstances, like results, in other words, that nature acts uniformly. This is my warrant, and my only warrant, for the inference, that what I have observed in many cases is true in others that I have not observed. _A Difficulty suggested._--But in what manner, now, shall this mere belief of mine, for it is nothing more, come to take its place as a general proposition, as positive categorical affirmation in the syllogism whose major premiss reads, All men are mortal? A law of the mind may be a sufficient explanation of my belief; but the science of syllogisms cannot take cognizance of laws of the mind, as such, and has nothing to do with beliefs, but is concerned only with the _forms_ in which an argument shall be presented. Those forms must be conclusive. How shall I convert, then, my conjecture, my plausible belief, in the present case, into that general positive affirmation which alone will answer the demands of the syllogism? _The Process explained._--The process is this: The precise result of my observation stands thus--_x_, _y_, _z_, are mortal. But I know that _x_, _y_, _z_, are so numerous as fairly to represent the class to which they belong. On the strength of this position, the inductive syllogism takes its stand, and overlooking the fact that there are some cases which have not fallen under my observation, _positively affirms_ what I only _believe_ and _presume_ to be true, and the argument then reads, _x_, _y_, _z_, are mortal. But _x_, _y_, _z_, are all men, therefore, all men are mortal. The general proposition thus reached by induction becomes, in turn, the major premiss of the deductive syllogism, which concludes, from the mortality of all men, that of Socrates in particular.