pure reason noun

1. Reason alone, without involvement of emotion, etc
2. In Kant, the power of grasping a priori forms of knowledge (philosophy)

pure science noun

Science considered apart from practical applications

reason /rēˈz(ə)n/

1. Ground, support or justification of an act or belief
2. A premise, esp when placed after its conclusion
3. A motive or inducement
4. An underlying explanatory principle
5. A cause
6. The mind's power of drawing conclusions and determining right and truth
7. The exercise of this power
8. Sanity
9. Conformity to what is fairly to be expected or called for
10. Moderation
11. Fair treatment, eg satisfaction by a duel, or doing one's fair share in drinking (archaic)
12. A remark, a sententious saying (Shakespeare)
13. Proportion (Spenser)

1. To exercise the faculty of reason
2. To deduce inferences from premises
3. To argue
4. To debate
5. To converse (Shakespeare)

1. To examine or discuss
2. To debate
3. To think out
4. To set forth logically
5. To bring by reasoning

reaˈsonable adjective

1. Endowed with reason
2. Rational
3. Acting according to reason
4. Agreeable to reason
5. Just
6. Not excessive
7. Not expensive
8. Moderate

Reasonably

reaˈsonableness noun

reaˈsonably adverb

reaˈsoned adjective

Argued out

reaˈsoner noun

reaˈsoning noun

reaˈsonless adjective

by reason of

1. On account of
2. In consequence of

do someone reason (obsolete)

1. To give someone the satisfaction of a duel
2. To drink without shirking

it stands to reason

It is obvious or logical

listen to reason

Listen to, and take heed of, the reasonable explanation, course of action, etc

no reason but (Shakespeare)

No reason for it being otherwise, hence, no possible alternative

principle of sufficient reason

That nothing happens without a sufficient reason why it should be as it is and not otherwise

pure reason

Reason absolutely independent of experience

within or in reason

Within the bounds of what is possible, sensible, etc