Demarais and D were involved in a fight. They were at a bar and both had been drinking. Demarais testified that he had been sitting at the bar with some friends when D, whom he did not know, approached him from behind, put him in a headlock, pushed him forward, and punched him several times in the face. Bystanders pulled D off of Demarais, and shortly thereafter, Demarais left the bar. D testified that he had approached Demarais at the bar because Demarais had been staring at him and he wanted to find out why. D contends a brief struggle then ensued. After Demarais left the bar, D noticed that his hand had been cut and he decided to go after Demarais to 'talk to him' about what Demarais had done. Demarais stated that D grabbed him from behind and punched him at least twelve times before Demarais fell to the ground and started to lose consciousness. In an effort to defend himself he pulled out a small knife and blindly slashed at D over his shoulder. D said he saw Demarais walking down the street, hollered at him to stop, ran towards him, and tackled him. They fell to the ground. After some struggle, D felt a pain in his side and became scared and angry. He testified he repeatedly punched Demarais in an effort to get Demarais to stop stabbing him. Demarais' eyes were swollen shut and he experienced a partial loss of vision. One tooth had been knocked out, and another was hanging by a thread. D suffered multiple stab wounds to his face, the back of his scalp, his neck, hand, and chest. The stab wounds were all superficial. The trial court judge instructed the jury as follows: 'To commit the offense purposely means that [defendant] acted with the conscious purpose of causing serious bodily injury or that he acted under circumstances where he was practically certain that his conduct would cause serious bodily injury.' The jury convicted D of aggravated assault. D appealed. D argues that a proper jury instruction would have told the jury that to convict him it had to find that it was his conscious objective to inflict serious bodily injury on Demarais and if he only acted under circumstances where he was practically certain his conduct would result in serious bodily injury to Demarais, the jury could not convict him.