The topic of subjective reason comes forth nicely in one essay.  Here’s part of an essay that Max Horkheimer wrote on Means and Ends. I think it’s worth reading through the introduction.

When the ordinary man is asked to explain what is meant by the term reason, his reaction is almost always one of hesitation and embarrassment. It would be a mistake to interpret this as indicating wisdom too deep or thought too abstruse to be put into words.

What it actually betrays is the feeling that there is nothing to inquire into, that the concept of reason is self-explanatory, that the question itself is superfluous. When pressed for an answer, the average man will say that reasonable things are things that are obviously useful, and that every reasonable man is supposed to be able to decide what is useful to him.

Naturally the circumstances of each situation, as well as laws, customs, and traditions, should be taken into account. But the force that ultimately makes reasonable actions possible is the faculty of classification, inference, and deduction, no matter what the specific content-the abstract functioning of the thinking mechanism.

This type of reason may be called subjective reason. It is essentially concerned with means and ends, with the adequacy of procedures for purposes more or less taken for granted and supposedly self-explanatory. It attaches little importance to the question whether the purposes as such are reasonable. If it concerns itself at all with ends, it takes for granted that they too are reasonable in the subjective sense, i.e. that they serve the subject’s interest in relation to self-preservation- be it that of the single individual, or of the community on whose maintenance that of the individual depends.

The idea that an aim can be reasonable for its own sake-on the basis of virtues that insight reveals it to have in itself without reference to some kind of subjective gain or advantage, is utterly alien to subjective reason.

This is also referred to as instrumental reason – the use of reason for a purpose.  In a setting of a common goal, the individuals participating in that goal are not interested in the ultimate mission or vision of the entity producing those things.  The individual tasks are divided into accomplishing something that is validated by other minds and rules.  The individual is assured that his or her own role is consonant with the vision.  If it is part of one’s employment, the entity’s vision and mission are not necessarily of prime importance to the individuals; they work, they get paid, and all jobs are pretty much the same.

There is a huge and largely unstated organizational culture in America, one which is learned by inference and rarely set down in words – the culture of the workplace, with its HR and potlucks, its PTO policies and social media rules, the laws in place by policy and procedure, the allocation of responsibility – by which most organizations are manifestly obedient, from rocket manufacturers to Forestry Service auditors.  That culture of the workplace is learned by intuition from the educational systems.  Many of the rules and roles of the workplace and society are outlined in the book of short essays by American minister and author Robert Fulghum, All I Really Need To Know I Learned in Kindergarten. See here for quotes.

There is a palpable certainty in America that much mischief is caused by individuals and organizations which, out of arrogance, do not care to follow the rules.  Mrs. Clinton learned a harsh lesson from the American voters recently as to her apparent sloppiness in the kindergarten rules.

The corollary of these utilitarian rules is the principle of objective reason.  In nowhere is there such a brilliant example of the contrast between these two ideas, similar on the face of it but different in substance, than in the principles of law.