While temporal considerations are of prime importance for chemical reactions, as well as for molecular stability, most chemical concepts are not explicitly formulated on a diachronic basis. It will be argued here that a formulation explicitly incorporating temporal and epistemological considerations enables us to treat chemical reactions and chemical substances on ontologically equivalent terms, instead of assigning a more fundamental status to the latter. After all, in collision theory, a chemical substance is just a collision complex that takes too long. (...) How long qualifies as “too long”, and “too long” in relation to what, are crucial questions that distinguish chemical substances from chemical reactions, and reversible reactions from irreversible ones, thereby introducing anthropocentric considerations into these distinctions. Too long for a lab chemist is very different from too long for an astrochemist studying chemical reactions between chemical substances in inter-stellar space on cosmological timescales. Examining several physical and chemical properties on the basis of which chemical substances are distinguished from one another, the role of temporal and anthropocentric considerations in defining molecular properties is emphasized. I conclude with some observations on the much-debated reduction of chemistry to other disciplines, arguing that such reduction depends on our aesthetic choices as to what kinds of observations demand explanation, and what kinds of explanation are acceptable. (shrink)

This paper recommends that chemistry educators shift to a different ‘idea of nature’, an alternative ‘worldview.’ Much of contemporary science and technology deals in one way or another with dynamic coherences that display novel and important properties. The notion of how the world works that such studies and practices generate (and require) is quite different from the earlier concepts that are now integrated into science education. Eventual success in meeting contemporary technological and social challenges requires general diffusion of an overall (...) outlook that focuses on creative generation of novel and useful coherences, replacing a worldview that concentrates on analysis of pre-existing items to minimum constituents. Such a shift in emphasis would amount to general adoption of a new basic model of how nature functions. Chemistry educators can and should provide leadership for this urgently-needed development. (shrink)