The scourging of Jesus was interrogation, not punishment

James Tissot, La flagellation de dos (1886-1894)

This is from the Passion narrative in John 18:38-19:6.

[38] Pilate . . . went out again unto the Jews, and saith unto them, "I find in him no fault at all. [39] But ye have a custom, that I should release unto you one at the passover: will ye therefore that I release unto you the King of the Jews?"

[40] Then cried they all again, saying, "Not this man, but Barabbas." 

 

Now Barabbas was a robber.

[19:1] Then Pilate therefore took Jesus, and scourged him. [2] And the soldiers platted a crown of thorns, and put it on his head, and they put on him a purple robe, [3] and said, "Hail, King of the Jews!" and they smote him with their hands.

[4] Pilate therefore went forth again, and saith unto them, "Behold, I bring him forth to you, that ye may know that I find no fault in him."

[5] Then came Jesus forth, wearing the crown of thorns, and the purple robe. And Pilate saith unto them, "Behold the man!"

[6] When the chief priests therefore and officers saw him, they cried out, saying, "Crucify him, crucify him." 

 

Pilate saith unto them, "Take ye him, and crucify him [yourselves]: for I find no fault in him."

Pilate presents a Jesus who has visibly just undergone brutal physical punishment and says he is showing the Jews this "that ye may know that I find no fault in him."

This only makes sense if the scourging, the crown of thorns, and the other abuse from the soldiers was a form of interrogation by torture, not a first round of preliminary punishments prior to the crucifixion itself. Pilate is saying, in effect, "Look: We beat him, we mocked and provoked him, we gave him forty stripes save one -- and he still didn't confess to anything. This is an innocent man."

Pilate had been expecting to elicit either a confession or some seditious threat -- something along the lines of Paul's "God shall smite thee, thou whited wall!" -- but Jesus didn't give him anything.