(_c_) Is his interest in the case an impartial one?

 

(_d_) Does he state his opinion positively and clearly?

 

(_e_) Are the non-personal authorities cited (books, etc.) reliable and

unprejudiced?

 

3. _The facts adduced as evidence_

 

(_a_) Are they sufficient in number to constitute proof?

 

(_b_) Are they weighty enough in character?

 

(_c_) Are they in harmony with reason?

 

(_d_) Are they mutually harmonious or contradictory?

 

(_e_) Are they admitted, doubted, or disputed?

 

4. _The principles adduced as evidence_

 

(_a_) Are they axiomatic?

 

(_b_) Are they truths of general experience?