Molecular structure is one of the dispositional attributes of the molecule and counted as an example of affordances. This attribute has been systematically exploited through the development of theories and practice of organic chemistry. (Ochiai 2023, pp. 141–149) The question to be addressed in this study is whether we can legitimately claim that this type of attribute is real. To answer the question, we first clarify what is worthy of the word ‘reality’ in scientific arguments. Whitehead claims that a physical substance like electron is a bundle of spatial-temporal experience. (Mesle 2008, p. 36) The contention is that we cognize the causal relationships of the physical world through the experience of events. What we cognize as real is not unchanging matter but various kinds of events we experience. Based on this recognition we examine the nature of affordances. Affordances are the context-relative dispositional attributes of {agent-world} complexes. (Harré 2014, pp. 77–91; Harré and Llored 2018, pp. 167–186) The affordance of a knife becomes actualized through our experience of cutting. In this way affordances are concerned with work or the function of something useful. They are materialized as tools. This suggests that affordances are real, and so is molecular structure. Molecular structure is characterized by a certain function which molecules show in organic synthesis. Other dispositional attributes of molecules that become actualized in the context of organic chemistry are also examined. We refer to the physical significance of wavefunctions as well, which we discussed in the previous study. (Ochiai 2023, pp. 359–367) Creating function, we expand a world we cognize as real. This view of the world we name ‘functional realism.’ Our conceptual scheme is supported by Quine’s holism.