Ernest Sosa in his paper “The Raft and the Pyramid: Coherence versus Foundations in the Theory of Knowledge” makes a distinction between a “normative and evaluative” justification and an epistemic justification by use of an example of a sick patient. This type of example is something I have also used in the past to show that one can be justified to hold a belief based upon pragmatic reasons and/or prudentalism. Take for consideration a patient who is dying in a hospital and is told there is a new experimental drug which ‘could’ possibly save their lives. The patient may not be familiar with the efficacy of the drug, but knows people with more positive dispositions statistically generally have a better prognosis. His practical justification for a belief that the new experimental drug will help him could be predicated upon pragmatic reason of merely wanting to survive, or prudential reasons as knowing it is better for him to survive so he can continue to support his family. In both cases, the justification for belief is not primarily contingent on the success rate of the new drug, which is information that the patient isn’t even purview to. His belief justification doesn’t arise from evidence, but from non-evidential reasons for he feels justified to hold a belief that the new drug will work.
However, this is where I think a distinction comes in of where we say that one justification may be sufficient to hold to a particular belief…but not to claim it as knowledge. Sosa notes that the epistemic justification, the justification that he knows the drug may work, of the infirmed patient would be the actual lab results and doctors diagnosis and prognosis. In other words, the patient can only say he knows or not the drug can even be successful if he has information provided to him about the drug and the doctors professional opinion about it’s possibility of success.
Patient: “I believe if I take drug x I will get better.”
This belief position can be justified for the pragmatic and/or prudential reasons above. At this point, one may ask…well, are they justified to believe that to be the case if drug x was merely a homeopathic drug? Or even a placebo? It is overwhelming well established as scientific fact that homeopathy does not work, but is there an argument to be made that *if* one believes that they will for again the pragmatic or prudential reasons give above, that they have a justified belief it will? Even if they are, it could never be an epistemic justification of knowledge since for that to be the case it would have to be true that homeopathy actually works…and that has been demonstrated to just not be the case. However, I would argue in this case that even given these parameters that a patient is never justified to believe homeopathy works. This isn’t because it is a clear false belief, as there are numerous arguments to be made about if are we ever justified to hold false or irrational beliefs if we gain some type of epistemic or physiological benefit from them…but because the patient who has actual medicine available to them with an established history to draw inference from that they work, is simply never justified to ever decided to take alternative medicine with out such a history.
In the case of the placebo, I think the patient is justified to believe it will work as they are basing their justification upon the advice of medical professionals that what they are taking will work, which is critical in how the placebo effect works, as it is predicated upon the belief that the patient has of an expectation that it will work.
In any of these situations, best case the patient is still only justified to hold a belief that the experimental drug will work, which doesn’t raise to the level of justification of knowledge, until there is sufficient justification to warrant a claim of knowledge over mere justified belief. This is why I hold “knowledge” and “justified belief” are not synonymous as in this example, the patient may be justified to hold the belief…but it isn’t knowledge unless there is sufficient data that the drug actually works and that information is provided to the patient where they can say they know it even “may” work. The patient can’t even say “I know it may work!” if they lack the epistemic justification (the knowledge of the efficacy of the drug), but is to me justified to say “I believe it will work!”. Notice the distinction between I make between “will work” in the believe case, and “may work” in the knowledge case. This is because the patient it seems to me would never be able to say “I know it will work!” unless if and only if the drug has a 100% success rate, and a belief doesn’t require that level of confidence. This is why there is different level of justification to meet for a belief claim vs a level of a knowledge claim, and one justification may be enough for to hold to a belief, but not sufficient enough to use that justification claim knowledge.