rationale

A set of reasons or a logical basis for a course of action or a particular belief.

• rational/ˈræʃənl/(adj)理性的
• rationalize/ˈræʃənəlaɪz/(v)合理化

• provide a rationale
• underlying rationale
• rationale for
• rationale behind
• clear rationale

1. 1.The CEO explained the rationale behind the restructuring — reduce costs without sacrificing quality. (reasoning)
2. 2.Critics argued that there was no scientific rationale for the new regulation. (logical basis)

• reasoning/ˈriːzənɪŋ/— the process of thinking logically
• justification/ˌdʒʌstɪfɪˈkeɪʃən/— a reason to show something is right
• logic/ˈlɒdʒɪk/— the reasoning behind something

from Latin "rationalis" (of reason) — "ratio" (reason, calculation)