Molecular magnetism: A philosophical perspective from a biased point of view

Contrary to a prevalent impression, most new discoveries and theories in the sciences are not merely additions to the existing stockpile of scientific knowledge. To assimilate them the scientist must usually rearrange the intellectual and manipulative equipment he has previously relied upon, discarding some elements of his prior belief and practice while finding new significances in and new relationships between many others. Because the old must be revalued and reordered when assimilating the new, discovery and invention in the sciences are usually intrinsically revolutionary. Therefore, they do demand just that flexibility and open-mindedness that characterise, or indeed define, the divergent thinker (T.S. Kuhn). These propositions constitute the central concepts for describing the work made by Dante Gatteschi in the framework of the development of the study of molecular magnetism and for understanding the sense of his own divergent pragmatism. The single molecule magnets properties exhibited by some mesoscopic molecular systems provide the basis for bridging the quantum world with the classic one. It is here stressed that these studies provide direct evidence for the type of information which can be elicited from a physical system. The obtained results emphasise that it is meaningless to conceive a direct measurement of a property of a quantum object. Therefore it is concluded that the information can be obtained only in indirect way and is determined by the world where the observer lives, in agreement with the existence of a well defined separation between the domain of the real objects and the information the observer may detect. In this sense molecular magnetism may provide a proper answer to the classical epistemological question concerning the possibilities and limitations of human recognition.