Reason has a central position in our western culture. This we westerners generally accept. I maintain, however, that that which we call reason is not an unanalysable property of the mind, but an expression of our human operational coherence in language, and that as such it has a central and constitutive position in everything that we do as human beings. We argue rationally in favour or against any case that we chose to reflect upon, even when we reflect upon reason itself, either to uphold it or negate it in one domain or another, by the very fact that we operate in language. As a result, different cultures differ not in rationality but in the implicit or explicit accepted premises under which their different kinds of discourse, actions, and justifications for actions take place. Accordingly, in my reflections upon reason, I shall endeavour to show its biological foundations as a phenomenon of our operation in language.

If we adopt the explanatory path of objectivity-without-parenthesis, reason appears as a constitutive property of the observer, that is, as a cognitive feature of his or her conscious mind through which he or she can know universals and a priori principles, and which, since it is accepted as given, can be described but not analysed. In this explanatory path, reason reveals the truth through a disclosure of the real by referring in a transcendental manner to what is as if independent of what the observer does. In this path, the rational is valid by itself and nothing can negate it; at most the observer can make a logical mistake, but nothing of what he or she does can destroy its transcendental cognitive power. Furthermore, in this explanatory path emotions do not contribute to the constitution of the validity of a rational argument, they may blind the observer to its binding power, but they do not alter it because it is founded on the real. As a result, in the explanatory path of objectivity-without-parenthesis the search for reality is the search for conditions that make an argument rational, and, hence, undeniable. Or, in other words, due to the nature of rationality in the explanatory path of objectivity-without-parenthesis, in it the search for reality is the search for the compelling argument.

Contrary to this, if we adopt the explanatory path of objectivity-in-parenthesis, reason appears as the distinction by an observer of the operational coherences that constitute his or her linguistic discourse in a description or in an explanation. Furthermore, it also becomes apparent that the operational coherences of the observer that constitutes reason are the operational coherences of the observer in his or her praxis of living in language. In this explanatory path, therefore, rationality is not a property of the observer that allows him or her to know something that exists independently of what he or she does, but it is the operation of the observer according to the operational coherences of languaging in a particular domain of reality. And, accordingly, there are as many domains of rationality as there are domains of reality brought forth by the observer in his or her praxis of living as such. In other words, in this explanatory path, the observer is aware that every rational system is a system of coherent discourses whose coherence results from the impeccable recursive application of the constitutive characteristics of basic premises accepted a priori. Or, what is the same, every rational system is founded on non-rational premises, and it is enough to specify some initial elements that through their properties specify a domain of operational coherences to specify a rational domain. Indeed, this is why every domain of reality is a domain of rationality. Still in other words, the coherence of the operation of the observer in language as he or she explains his or her praxis of living constitutes and validates the rationality of the operation of the observer as he or she constitutes a domain of reality.

Furthermore, an observer in the explanatory path of objectivity-in-parenthesis is aware that, although his or her emotions do not determine the operational coherences of any domain of reality in which he or she may operate, they determine the domain of operational coherences in which he or she lives and, hence, the domain of rationality in which he or she generates his or her rational arguments. Indeed, biologically, what an observer connotes when ascribing an emotion or a mood to some other being through the distinction of a particular configuration in the flow of its actions is a particular dynamics of inner body dispositions (which, of course, includes the nervous system) that determines the domain of actions in which that being can operate at that moment. It is because of this that I call emotions and moods body dispositions for actions, and distinguish moods as emotions in which the observer does not distinguish directionality or possibility of an end for the type of actions that he or she expects the other to perform.

Finally, as an observer in the explanatory path of objectivity-in-parenthesis becomes aware of his or her biology in observing, he or she also becomes aware that his or her emotional flow entails also a flow through different rational domains. Or, what is the same, such an observer becomes aware that the rational domain in which he or she constructs his or her rational arguments may change as his or her emotions and moods change. In other words, in this explanatory path the observer becomes aware that a change in emotion or mood constitutes a change in the operational premises under which his or her praxis of living takes place, and therefore in what an observer may distinguish as the accepted a priori conditions that support his or her rational explanatory arguments. That we know that, in daily life, this is the case is apparent when we say something like this: "Do not pay attention to his argument; he is angry; as he becomes serene he will think differently." Due to all this, in the explanatory path of objectivity-in-parenthesis, the observers who meet in a disagreement do not face each other as antagonists in the search for a compelling argument. Indeed, what they do is to search for a domain of coexistence in mutual acceptance (understanding), or for the acceptance of their disagreement with separation in mutual respect, or for a responsible mutual negation.

As a general summary, and in answer to questions that I asked at the beginning of the first section, I can say that it follows from all this that, in the explanatory path of objectivity-in-parenthesis, we as observers become aware: a) that reason constitutively does not, and cannot, give us an access to an assumed independent reality; b) that the compelling power of reason that we live in our rational lives is social, and results from our implicit a priori (that is, non rational) adoption of the constitutive premises that specify the operational coherences of the conversational domains in which we accept the arguments that we consider rationally valid; c) that we cannot force anyone, through reason, to accept as rationally valid an argument that he or she does not already implicitly accept as valid by accepting the constitutive premises of the conversational domain in which it has operational coherence; and d) that all that we can do in a conversation in which there is no previous implicit agreement is to seduce our interlocutor to accept as valid the implicit premises that define the domain in which our argument is operationally valid.