“Inference” is a tricky category. We can think of plenty of instances for which we can specify precise criteria for successful inference, but these are swamped by the plenitude of situations in which successful inference from circumstances can be judged only on a rough-and-ready, close-enough sort of way. I can infer the time of day from the illumination filtering through my bedroom curtains, and that is ordinarily a satisfactory guide; but some mornings are exceptionally cloudy, or unexpectedly bright, and that pattern of inference really only works during the transition from night to day (it’s harder to distinguish 10:00 from 11:00 than 5:30 from 6:30 this time of year), some of us are better-attuned to morning light than are others, and of course some days the government instructs us to change our clocks by an hour. And even under the optimal circumstances, most of us can determine “It’s time to get up” but not “It’s exactly 6:47.” We do well enough (relative to particular expectations) almost all the time (but not absolutely always) by inferring time from bedroom-illumination; yet illumination-inference differs profoundly from consulting a radio-controlled digital timepiece.
Similarly, when Margaret and I need not to speak — when our infant children were sleeping, or when we’re observing an interval of silence, if we’re at a concert or in a gallery, or even if we’re playing Charades or Pictionary — we know one another well enough that we can often communicate effectively by gestures and facial expressions. Similarly, particular musical compositions generally evoke predictable sentiments among listeners. Colours apparently tend to cue particular physiological and behavioural responses. Scents, textures, noises, ambient temperatures, architectural and decorative spaces (awkward phrasing, can be improved), provide the basis for inferred responses. Some of these are highly predictable, some are more idiosyncratic, and the more aware we are of the degree to which a particular sensuous expression can be relied upon to evoke a particular response, the more successfully we negotiate the semiotic environment.