Nomic and normic concepts

At this point it is important to note a limitation of Kuhn's account acknowledged by Kuhn himself. In his later work Kuhn suggested that some important scientific concepts were not acquired by the processes discussed so far, that is, through learning similarity and difference relations by ostension, leading to the formation of contrast sets that can be represented by concepts forming a kind hierarchy. To mark this distinction, he introduced the term 'normic' to designate concepts acquired by...

The problem of the equant point

In the previous section we established that the Copernican account of celestial motions and the simplest Ptolemaic account use the same conceptual structure. The same result was established in the previous chapter for the Averroist account and the Ptolemiac account. figure 61. (a) Ptolemaic eccentric-plus-equant model for an outer planet, compared with (b) Copernican model with 'concealed equant' atE'. figure 61. (a) Ptolemaic eccentric-plus-equant model for an outer planet, compared with (b)...

And the copernican revolution

In this chapter we have examined the conceptual structures of Ptolemaic astronomy, Copernican astronomy in its original form, and Kepler's variant as it appeared in the Astronomia Nova of 1609. This has led to a dramatic reappraisal of the Copernican revolution. Rather than a clear incommensurability with Ptolemaic astronomy introduced by Copernicus, we have seen that Copernican astronomy and Ptolemaic astronomy had highly similar conceptual structures, and that Ptolemaic astronomy itself...

Galileos discoveries and the conceptual structure of astronomy

At the time of Copernicus all natural philosophers in the Latin West agreed that the earth was the center of the cosmos, and that celestial objects somehow moved around it. The main physical constituents were a series of spherical shells, centered on the earth. Celestial objects like planets and stars were minor imperfections in these shells. They were carried around the heavens by the spheres as they moved (Swerdlow 1976 Van Helden 1985). How planets moved was a matter of bitter dispute....

The conceptual structure of keplers astronomy

By the time Kepler began his career in the 1590s all the information we have just reviewed was readily available to him. In the Mysterium Cosmographicum, published in 1596, he opted for fluid heavens through which planets move freely within the confines of heliocentric shells. These shells are no longer physical but purely geometrical structures defined by his ingenious Platonic solid construction. But the motions of these planets are still decomposed into circles, and the frame for the concept...

References

Why are different features central for natural kinds and artifacts The role of causal status in determining feature centrality. Cognition 69 135-178. Ahn, W. K., & Dennis, M.J. 2001. Dissociation between categorization and similarityjudgement Differential effect of causal status on feature weights. In U. Hahn & M. Ramscar (eds.) Similarity and Categorization, pp. 87-107. Oxford Oxford University Press. Ahn, W. K., Kalish, C. W., Medin, D. L., & Gelman, S. A. 1995. The...