Despite their differences, all previously reviewed accounts have something in common. That is, they adhere to monism with respect to self-knowledge. What they all do is focus on one specific instance, provide what seems at least a prima facie suitable explanation and then try to generalize it to all other cases. If they realize the generalization cannot be complete, they downplay the significance of those instances of self-knowledge their preferred accounts cannot accommodate. Yet, these moves are problematic.
For instance, there is no doubt that quite a lot of our self-knowledge is obtained in a third-personal way through inference to the best explanation. While this is hardly disputable when we consider knowledge of our biases or unconscious mental states, it is implausible when applied to our knowledge of our occurrent sensations. We do not look at our moaning and screaming and infer that it must be caused by pain.
Similarly, there is little doubt that when we deliberate what to believe, want or intend doing by weighing reasons, we have first-personal self-knowledge of those mental states. But it would be hard to believe that these are the only relevant cases of first-personal self-knowledge—as the case of our knowledge of our occurrent sensations shows—or that there is nothing philosophically and epistemologically interesting in third-personal self-knowledge.
At the heart of The Varieties of Self-Knowledge lies the rejection of monism and the subsequent embracement of pluralism. Namely, the idea that, depending on the kind of mental state at issue, it can either be known in a first- or in a third-personal way. Furthermore, on closer inspection, there is also a plurality of methods we can apply to obtain third-personal self-knowledge. Finally, the account of first-personal self-knowledge too will subtly differ, depending on the kind of mental state at issue.
So let us have a look at the plurality of methods we employ to obtain third-personal self-knowledge of our dispositional mental states (ranging from dispositional propositional attitudes, to the dispositional elements of emotions). We have already mentioned inference to the best explanation. One thing worth-emphasizing in this connection is the fact that only in our own case the evidential basis of the inference may comprise, beside outward behavior, also inner promptings. The case of Emma’s realization of her love for Mr. Knightly is paradigmatic:
Emma’s eyes were instantly withdrawn; and she set silently meditating in a fixed attitude, for a few minutes. A few minutes were sufficient for making her acquainted with her own heart. A mind like hers, once opening to suspicion, made rapid progress. She touched—she admitted—she acknowledged the whole truth. Why was it so much the worse that Harriet should be in love with Mr. Knightley than with Mr. Churchill? Why was the evil so dreadfully increased by Harriet’s having some hope of return? It darted through her, with the speed of an arrow, that Mr. Knightley must marry no-one but herself.
Furthermore, we can employ simulation to find out whether, for instance, we are courageous, trust-worthy, loyal, etc. For instance, we may imagine being alone in a house in the middle of nowhere, late at night, half asleep in bed. We may imagine hearing a creeping sound from the basement and then attend to what we would do in that predicament. Depending on the outcome of the simulation, we may self-ascribe the property of being courageous (or not).
Another method we may use is a “hermeneutical” one. If one has just acquired a new psychological concept, like, for instance, egotistical, one may go through its characteristic notes (i.e. excessively conceited or absorbed in oneself) and realize that one is instantiating them, thereby arriving at the self-ascription of that psychological property. Sometimes, this newly acquired concept can bring about a “switch of aspect” with respect to oneself. For instance, up to a certain point one might have thought of oneself as just not very sensitive. Upon acquiring the concept of being ruthless and going through its characteristic notes (having or showing no pity or compassion for others), one may look at oneself differently. So there is a sense in which having more psychological concepts helps us know ourselves better, by enabling us to make subtler distinctions, which could have important ethical consequences. Moreover, it could so happen that we may alternate between seeing ourselves as not very sensitive and seeing ourselves as ruthless, thus undergoing the alternation between different aspects, characteristic of (at least some cases) seeing-as. I believe that certain alleged cases of self-deception too can be explained through this kind of template.
Sometimes we gain knowledge of our dispositional mental states through testimony. If you have reasons to trust a person (or at least no reason to distrust them), and if they sincerely tell you that you are intimidating, then you have justification to believe so and you would count as knowing it. Indeed, in many cases of dispositional psychological properties, which constitutively depend on the interaction with others, the best way to gain knowledge of them is through their testimony. There is a sense, then, in which it is true that self-knowledge may depend on mirroring ourselves in others.
This metaphor is even more appropriate when we go through a process of identification with others, or indeed with characters in a novel or a film, and we thereby realize that certain things, which are true of them, are actually true of us too. If you read Madame Bovary and you identify with the protagonist, Emma, you may realize that her being bored was key to starting the affair with Léon, which eventually led her to commit suicide. Through such an identification, you may realize you are similarly bored with your life, and see that that may well be the cause of your unruly behavior. Our Buildung goes through such processes and one of the cognitive values of at least some literary and cinematographic genres is to give us means to know ourselves (and others) better.
Thus, far from being philosophically and epistemologically uninteresting, third-personal self-knowledge is a largely underexplored yet exciting area of inquiry. Furthermore, it is the kind of self-knowledge, which affords us with the most interesting truths about ourselves. Yet, since it involves complex epistemic methods, it does not come “for free”, and it can go wrong in all sorts of ways. Thus, transparency and authority do not hold in that case.