There are three stages of inquiry, demanding as many different kinds of reasoning governed by different principles. They are,
1, Retroduction, forming an explanatory hypothesis[;]
2, Deduction, tracing out the consequences that would ensue upon the truth or falsity of that hypothesis; and
3, Induction, the experimental testing of the hypothesis by inquiring whether its consequences are born out by fact, or not.
Retroduction
The recommendations of an explanatory hypothesis are
1st, verifiability; 2nd, simplicity; 3rd, economy.