(1) Your clear reasoning is quite correct.

(2) This kind of reasoning is deeply perverse.

(3) Their reasoning capacity must be developed.

(4) I can't quite follow your reasoning.

(5) I didn't follow his line of reasoning.

(6) The reasoning behind her conclusion is impossible to fault.

(7) Many people challenged the reasoning behind the proposal.

(8) His reasoning can't be flawed.

(9) His close reasoning gave fibre to his argument.

(10) I don't follow your line of reasoning.

(11) There's a fatal flaw in your reasoning.

(12) She seemed to have lost her powers of reasoning.

(13) His argument is based on fallacious reasoning.

(14) Your reasoning on this point is faulty.

(15) The same reasoning applies to the current situation.

(16) What is the reasoning behind this decision?

(17) This line of reasoning is faulty.

(18) The line of reasoning will only lead you up another blind alley.

(19) His reasoning is perfectly sound, but he misses the point.

(20) The implication of this line of reasoning is that globalization of capital is destructive.

(21) I cannot accept the reasoning that led the trial court to its decision.

(22) His reasoning is based on the premise that all people are equally capable of good and evil.

(23) His argument does not rest on reasoning or on experiment[sentencedict.com], but on authority.

(24) I spent hours reasoning out the solution to the puzzle.

(25) The reasoning seems rational.

(26) Even so, perception still dominates reasoning.

(27) I was a bit slow off the mark/on the uptake there - I didn't follow his reasoning at all.

(28) The test has scores for verbal skills, mathematical skills, and abstract reasoning skills. Sentencedict.com

(29) She's absolutely determined to go and there's just no reasoning with her.

(30) "It's freezing outside, you must be cold" is an example of a priori reasoning.