Herbert Simon 1983, Reason in human affairs

In reasoning:

there are no conclusions without premises.  ????? ????

Reasoning processes take symbolic inputs which are axioms, induced from observations or simply posited ???

The rules of  inference are not a product of reason.

herbert Simon 1983, Reaon in human affairs  (P. 5)


In the domain of reasoning,  “no conclusions without premises.”

Reasoning processes take symbolic inputs and deliver symbolic outputs. The initial inputs are axioms, simply induced from empirical observations, or even more simply assumed. Moreover, the processes that produce the transformations of inputs to outputs (rules of inference)  are not the products of reason. Axioms and inference rules together constitute the fulcrum on which the lever of reasoning rests.; This ineradicable element of arbitrariness has two important consequences:

1- First, it puts forever beyond reach an unassailable principle of induction that would allow us to infer infallible general laws, without risk of error, from specific facts, even from myriads of them. No number of viewings of white swans can guarantee that a black one will not be seen next. Whether even a definite probability statement can be made about the color of the next swan is a matter of debate, with the negatives, I think, outnumbering the affirmatives.

Further, the foundations of these inductions—the facts—rest on a complex and sometimes unsteady base of observation, perception, and inference. Facts, especially in science, are usually gathered in with instruments that are themselves permeated with theoretical assumptions. No microscope without at least a primitive theory of light and optics; no human verbal protocols without a theory of short-term memory. Hence the fallibility of reasoning is guaranteed both by the impossibility of generating unassailable general propositions from particular facts, and by the tentative and theory-infected character of the facts themselves.

2- Second, the principle of “no conclusions without premises” puts forever beyond reach normative statements (statements containing an essential should)  whose derivation is independent of inputs that also contain should’s. None of the rules of inference that have gained acceptance are capable of generating normative outputs purely from descriptive inputs.   (shown by by Ayer, in Language, Truth, and Logic,  rev. ed. (New York, 194.6))  The analogy to “no conclusions without premises” is “no ought’s from is’s alone.”

Thus, whereas reason may provide powerful help in finding means to  reach our ends, it has little to say about the ends themselves.

 3- There is a final difficulty, first pointed out by Godel, that rich systems of logic are never complete—there always exist true theorems that cannot be reached as outputs by applying the legal transformations to the inputs.

Reason, then, goes to work only after it has been supplied with a suitable set of inputs, or premises. If reason is to be applied to discovering and choosing courses of action, then those inputs include, at the least, a set of should’s, or values to be achieved, and a set of is’s, or facts about the world in which the action is to be taken. Any attempt to justify these should’s and is’s by logic will simply lead to a regress to new should’s and is’s  that are similarly postulated. (p. 5,6,7)

 The  reason is wholly instrumental. It cannot tell us wehere to go; at best it can tell us how to get there. (p.8)

 Our postulation of a “we” is a basic assumption about what is good and what is evil.  (p. 9)

Probably the greatest sense of outrage that Mein Kampf
generates stems from the sharpness of the boundary Hitler
draws between “we” and “they.” Not only does he give
priority to “we,” but he argues that any treatment of
“they,” however violent, is justifiable if it advances the
goals of “we.”            (Herbert Simon, Reason in human affairs, 1983, p.9)

 Amir: Simon argues that disagreements are many times not the result of wrong reasoning, it is in goodness of facts and values.  Facts canbe ignored by agenda setting and values are manipulated by emotional arousal and cultural shift.


when a position is declaimed

with passion and invective, there is special need to

examine carefully both its premises and its inferences. We

have learned this, but we do not always practice it. Regrettably,

it is precisely when the passion and invective resonate

with our own inner feelings that we forget the warning

and become uncritical readers or listeners.  (p.10)


Since 11 April 2023: 975 total views,  6 views today