2/ Defence of the idea that axiology belongs in the theoretical sphere
We need to ask ourselves why axiology (apart from the fact that it has been confused with the practical science of morality) can spontaneously appear to belong to the practical sphere.
First of all, there is perhaps a tendency to think that the problem of values, if solved, would necessarily have consequences for our actions, and would radically change our way of life, since if we could determine what is most valuable - which is obviously not yet presupposed here - then we would have identified the supreme goal that we should aim for in our existence.
This idea seems to present two difficulties (leaving aside that of the possibility of such a discovery).
First of all, just because the determination of what has - or does not have - a value can radically change human conduct, behaviour and action does not mean that axiology is a practical discipline. This could only be done if we were able to posit that this change in behaviour constituted the essence, or at least the ultimate end, of axiology.
However, the idea that I am going to try to defend is that this relationship to action is inessential for axiology, that it is only secondary, derivative.
Let us make an analogy: it is not because a human being walks that we can say that he is legs, or that walking constitutes his essence - as a result, we will not understand a human being if our reflection on him is a study, however thorough, of his walking. Similarly, just because axiology can have practical consequences for human action does not mean that it is in itself a practical science, and that we will understand its profound nature by determining what behaviour it should lead us to.
To sum up my position, axiology is a fundamentally theoretical science that can have practical consequences.
On the other hand, it does not seem that if we succeed in determining what has the greatest value, we would at the same time identify what must constitute human's ultimate end.
Let us recall this idea, which we have already proposed in our distinction between value and end 1, according to which it would be possible for what has the greatest value to be harmful to man or indifferent to him.
If this were the case, then we would not necessarily have to take this supreme value as our goal, but taking note of the nature of this value in itself, it would be possible for us to prefer to orient our life according to a more relative value, namely that of what is good for human being.
Unlike the notion of duty, value is not linked to any notion of obligation: it does not, therefore, compel acceptance. It imposes itself, just as the truth imposes itself, but does not oblige, any more than science obliges scientists or man in general to accept this or that idea.
Determining that something has a value, if that were possible, would not lead to a policed world, where all of us would be forced to adopt these values, but to an 'existentialist' world, where everyone would choose either to adopt real values or simply human values, i.e. what has value for us. This is why we believe that the project of an axiology and the existentialist doctrine are fundamentally compatible, an articulation that we unfortunately do not have the opportunity to consider here.
We can arrive at the same result from another point of view: even if we identified the supreme value, our action would not necessarily take it as its goal, because it is not the value but the nature of human action that must determine the goal of that action.
Human action depends on a huge number of factors: it involves a body, the unconscious, desire, feelings, society - in short, it is determined by psychological, physiological, sociological and other factors. I am not sure that value can slip into the interplay of these factors and subvert them, so as to become the criterion according to which action will take place. On the other hand, I am not sure that it should, i.e. that it is desirable for human action to cease to be determined by desire, feelings, etc., in order to become the criterion according to which action takes place.
This view may come as a surprise, but it is implicit in the idea that axiology is not concerned with the (human) good, or with values relating to human beings, but with real value, considered independently of human beings.
So we can understand why axiology is not for us a practical science, nor a human science: its aim is not to grasp the nature of what is good for human, it may not lead to any change in human's behaviour, and if it has any possible consequences for human action, this is not the essential aim of axiology, but only an accidental consequence for it.
Thus the possible results of axiology would be of no more practical interest to us than a search as disinterested as that which seeks to identify the exact size of some celestial object whose distance eliminates any attempt at exploration.
So we can see what, for us, makes axiology a theoretical science: it does not seek to bring its object into existence, but to discover a certain 'property' in objects, in other words a value. Its gaze is not fixed on human, as the human sciences are, but is turned towards the world, like mathematics, physics, biology, and more generally towards all the contents of meaning. It is the direction of this gaze that would bring axiology closer to the hard sciences than to the human sciences - and not the degree of certainty of its results, which we do not yet know.
Our hypothesis can be summed up as follows: axiology, if this discipline has any meaning, is a theoretical science, capable of engendering a number of practical consequences, whose gaze is not turned towards man but towards the world as a whole, or rather as a jewel case, of all possible things of value.
1. Cf Book I