“much reasoning” is correct and usable in written English.
You can use it when you want to describe a situation that involves a lot of thought or making decisions with careful consideration. For example, “The lawyer used much reasoning to argue her case in court.”.
But rarely has there been much reasoning behind the rules.
"It didn't take much reasoning, this mural would be destroyed," Mr. Solum said.
When my husband accused me of saving too much, I realized that there wasn't much reasoning behind my recordkeeping.
Beheading, crucifixion and hand-lopping did not require much reasoning because these punishments are part of the penal code of countries such as Saudi Arabia.
It's a subject on a very short cycle, and it will keep returning for as long as rape does; there is not much reasoning with people who think that this is the aspect that matters the most.
It is essential for much reasoning and decision-making, both individual and collective.
Within inquiry instruction, low reasoners had much higher reasoning transfer scores when placed in homogeneous groups (n = 3, Mhomogeneous = 4.00; n = 9, Mheterogeneous = 1.89; F = 6.78, p = 0.02; see Table 3).
It is obvious that much metaphysical reasoning is, or purports to be, reasoning in the strict sense, which is to say that its form is deductive.
The attempted alliance, untenable on both sides, produced much tortured reasoning and led to ruinous schisms.
Because of the nature of the objects of metaphysics, this latter kind of knowledge does not involve logical inference as much as reasoning by analogy or what Maritain calls ananoetic knowledge.
One of these is reminiscent of the first part of Aquinas's much discussed reasoning in De ente et essentia, c. 4, which begins from the fact that one can understand what something is without knowing whether it actually exists.
