It is impossible to say just what I mean!
But as if a magic lantern threw
the nerves in patterns on a screen.
–T. S. Eliot, “The Love Song of J. Alfred Prufrock” (1917)
If we wish to discern whether anything is beautiful or not, we do not refer the representation of it to the object by means of understanding with a view to cognition, but by means of the imagination (acting perhaps in conjunction with understanding) we refer the representation to the subject and its feeling of pleasure or displeasure. The judgement of taste, therefore, is not a cognitive judgement, and so not logical, but is aesthetic-which means that it is one whose determining ground cannot be other than subjective. Every reference of representations is capable of being objective, even that of sensations (in which case it signifies the real in an empirical representation). The one exception to this is the feeling of pleasure or displeasure. This denotes nothing in the object, but is a feeling which the subject has of itself and of the manner in which it is affected by the representation.
—Immanuel Kant, Critique of Judgment (1790), SS 1. The judgement of taste is aesthetic.
Now, I would argue that the same applies to intelligence. To the extent that we believe in such a thing as a “beautiful mind,” the very last way we should ever expect to identify one would be by means of IQ testing or neurological analysis. Of the many areas of research in which the writings of Kant enjoy an enduring influence, one of the most significant is the field of Phenomenology, a branch of philosophy which (along with the Pragmatism of the American psychologist William James) first arises as an aggressive attack against Experimental Psychology. Though the very same could be said of Freud: psychoanalysis arose a critical rebuke to the brilliant inanity of Helmholtz, Fechner and Wundt.
But does anyone write on this stuff intelligently, or at all today, and in a way which combines the very best of Art History and the History of Science?
Or, have a look at William James’s The Varieties of Religious Experience, considered one of the greatest books of the 20th century.