Possible Clues:

• Of reasoning, from cause to effect - in Latin
• Sort of reasoning it's time for fooling or idiocy, primarily
• One in charge of order engaged in fine reasoning
• Known beforehand
• Philosopher's term
• Before May at No 10 begins 'Remain' initiatives, this reasonably needs to be deduced rather than observed
• Carnival scene's penned in time for fooling theoretically
• Before May begins 'Remain' initiatives, this reasonably needs to be deduced rather than observed
• Derived by logic, without observed facts (Latin)
• Involving deductive reasoning