Subjective Uncertainty and Causality
Let's imagine asking Mary Poppins which of the two medical colleagues—the dentist or the neurologist—is correct.
The question would generate a kind of agitation based on internal uncertainty; therefore, the notions of certainty and uncertainty refer to the subjective epistemic states of human beings, and not to states of the external world, because there is no certainty or uncertainty in that world. In this sense, as we have mentioned, there are an inner world and an external world that both do not adhere to canons of uncertainty, but rather to probability.
Mary Poppins may be subjectively certain or uncertain as to whether she is suffering from TMDs or a neuropathic or neuromuscular form of OP. This is because "uncertainty" is a subjective, epistemic state below the threshold of knowledge and belief; hence the term.
Subjective Uncertainty
Without a doubt, the term ‘subjective’ alarms many, especially those who aim to practice science by pursuing the noble ideal of ‘objectivity,’ as this term is perceived by common sense. Therefore, it is appropriate to make some clarifications on the use of this term in this context:
‘Subjective’ indicates that the probability assessment depends on the information status of the individual who performs it.
‘Objective’ does not mean arbitrary.
The so-called ‘objectivity,’ as perceived by those outside scientific research, is achieved when a community of rational beings shares the same state of information. But even in this case, one should more properly speak of ‘intersubjectivity’ (i.e., the sharing of subjective opinions by a group).
In clinical cases—precisely because patients rarely possess advanced notions of medicine—subjective uncertainty must be considered. Living with uncertainty requires us to adopt a probabilistic approach.
Causality
Causality indicates the lack of a certain connection between cause and effect. The uncertainty of a close union between the source and the phenomenon is among the most challenging problems in determining a diagnosis.
In a clinical case, a phenomenon (such as a malocclusion, a crossbite, an openbite, etc.) is randomly associated with another phenomenon (such as TMJ bone degeneration); when there are exceptions for which the logical proposition is not always true (but it is most of the time), we will say that the relation is not always true but it is probable.