In light of these comments, we must add to what we said above when we
distinguished Weber’s ideal-types from idealized notions in the natural sciences
(such as a frictionless surface). We need to see that what Weber himself suggests
about the similarity between his notion of ideal-types and idealized notions
in economics can be misleading by misrepresenting his own intentions or the
true originality of his notion. We saw above that Weber suggests a parallel
between his notion of ideal-types and the appeal to “rational economic man”
as an explanatory tool in economics. Something further in that vein he says is
this, the import of which must not mislead us:
For the purposes of a typological scientific analysis it is convenient to
treat all irrational, affectually determined elements of behavior as factors
of deviation from a conceptually pure type of rational action. For example
a panic on the stock exchange can be most conveniently analysed by
attempting to determine first what the course of action would have been
if it had not been influenced by irrational affects; it is then possible
to introduce the irrational components as accounting for the observed
deviations from this hypothetical course. (Weber 1978 1:6)