The term apodicity means certainty arrived at through evidence. In psychological usage it refers to experiential knowledge. Knowledge is apodictic for me when, because of my own experience, I cannot congruently doubt it. Clearly one can go through the motions of doubting anything as an intellectual exercise, but, in practice, there are many things in life which I do not doubt because I have experienced them for myself.
In order to get this definition clear, let us consider some other cases. There are, for instance, things which one does not doubt because one has heard about them from a good authority. I do not doubt, for instance, that it takes light less than ten minutes to travel here from the sun. These things may be within the class "undoubted" for me, but they are not apodictic. Similarly there may be things which one has worked out for oneself but of which one has no direct experience. I might infer that dinner is ready from the fact that the children have all gone downstairs. I might not have any doubt about it but this is not apodictic knowledge, it is an inference. That dinner is ready will become apodictic for me when I see it on the table or, if I am the cook, when I take it out of the oven.
We can see, therefore, that there are many things in our minds which influence us which are not, in fact, apodictic. Indeed, the great majority of things which we think we know, we do not know at first hand or from the experience of our own senses. Does this matter? In many practical situations, probably not. In the quest for peace of mind, however, it may well become important. In my practice as a therapist, I encounter many people whose lives have become detached from a grounding in real experience. It is very common for intimate relationships, for instance, to be forums for interminable distressing conversations which are composed almost entirely of non-apodictic material. And, again, there are ways of thinking and talking commonly encountered in groups which have a distinct feeling of unreality about them. Appealing to apodicity, therefore, can be a way of grounding oneself or another person.
A client says to me "I am out of touch with my feelings. I never express what is going on inside me." I look at the client. The client's face is flushed. I can see the evidence of emotion in the pallor of the skin, in the tensing of the brow, the angle of the mouth, the look in his eyes. It is apodictic for me that this is not an emotionless person and I am having no difficulty reading what his feelings are. I do not therefore take the client's statement at face value. I say: "Is this your own view of yourself or is it what someone else says about you?" The client then tells me that it is not his own view, but rather that his wife is always telling him he is not expressing his feelings and he feels very hurt about this.
This example shows up, I think, a common pitfall in therapy. If we simply reflect what the client says, in the name of being person-centred, there is a real danger that we deny the evidence of our senses. It also illustrates the fact that, for this client, at least, the way to peace of mind may lie in the direction of reestablishing faith in his own experience rather than relying upon what he has been told by others.
Husserl believed that certainty, if it was to be found at all, had to lie somewhere in an appreciation of our direct sense experience. The Buddha was of the same opinion. When he was staying in the land of the Kalama people he gave a talk which included the following:
Now, Kalamas, do not go by hearsay, nor by what is handed down by others, nor by what people say, nor by what is stated on the authority of your traditional teachings. Do not go by reasoning, nor by inferring, nor by argument as to method, nor from reflection on and approval of an opinion, nor out of respect, thinking a recluse must be deferred to. But, Kalamas, when you know of yourselves: "These teachings are not good: they are blameworthy: they are condemned by the wise: these teachings, when followed out and put in practice, conduce to loss and suffering" - then reject them. (Anguttara Nikaya,i. 188, in Woodward 1973, p.189)
The path to peace of mind has to be rooted in "your experience of the senses" and the certainty that comes to us from knowing things directly. Such knowledge changes people in a way that other types of knowing do not. Knowing how long it takes a spaceship to go from earth to Mars is not likely to change me as a person. Going on a spaceship to Mars myself would probably change me. Therapy has to incorporate an experiential element. Therapy is a quest for what is already apodictic for the client and also a quest for new experience which will have a noticeable impact. In this regard it is important that what the client talks about may or may not be apodictic material but, the therapy relationship itself, the experience that the client has of the therapist, is always something directly and inescapably perceived and experienced. The apodicity of the relationship itself, however, may not be impactful unless it is brought into focus as an object of attention.
Apodicity is an experience. It is the experience of having something demonstrated to be unquestionably true. Apodicity refers to what happened to Archimedes when his bath over-flowed leading him, in a flash, to the realization that the volume of an irregular solid could be measured by the volume of water it displaced. Apodicity refers to realizations, to "eureka moments". These are also moments of therapeutic insight or of artistic creativity.
Such occasions change one. In a sense, therefore, apodictic experience is like a one way ratchet. You can't go back. Experiences like having a baby or nearly dying leave one a different person and it is impossible to return to how one was before. Good therapy would be apodictic experience that left one in better shape. However, much such experience has both a positive and a negative aspect. Many people have been made into better of greater people by tragedy, for instance. Spiritual awakening will also fit into this category. Although there is a world of difference between spiritual awakening and what happens in a good deal of psychotherapy, in principle, one feels, this should not be the case. Both should equally be concerned with liberating the person through apodictic experience.