The kid held the pencil between her thumb and index finger and wobbled it about. “Is the pencil straight or is it curved,” she asked.
“It’s straight,” he replied. “The wood is inflexible it won’t bend without breaking. It only seems curved because of the way your mind is processing the light entering your eyes. It’s an illusion.”
The kid looked confusedly at him. “But what you saw was a curved pencil right? You didn’t see a straight one?”
“No,” he replied, “I did not see a straight one.”
“You saw a curved pencil.”
“Yes I saw a curved pencil.”
The kid smiled, “see the explanation you gave about your mind processing the light entering your eyes merely describes how you came to experience what you saw. It doesn’t dismiss your phenomenological experience of it. In your reality, the pencil is curved.”
The kid held the pencil up again. This time with a firm grip on it. “Straight or curved?”
“Why would you say that?”
“It’s straight,” he replied. She looked at him as though she was waiting for him to elaborate. “It’s straight. The wood is inflexible it won’t bend without breaking.”
The kid slumped down onto the couch and craned her neck backwards as though stretching to see the plaster ceiling. She stayed like that for a while with a frown on her face like she wanted to change something about it, but couldn’t decide what–if anything–would make it better. They sat in silence. He was tempted to pull out his phone but didn’t because he felt it might be rude.
“How?” she said when she finally felt like saying something.
“How did you see the pencil when it was straight?”
“I don’t follow.” He didn’t follow.
The kid looked at him like he was a failed lego construction project that she wanted to smash and start all over. She took a breath and repeated her question. “How did you seethe pencil when it was straight?”
“Oh. Well my mind received input about the orientation and color of what I’m seeing and my mind organized and processed this data by comparing it to similar inputs I experienced in the past.”
“So basically the same.”
“Same as what?”
“As when you saw the curved pencil. In both cases, do either the straight pencil or the curved pencil exist purely, apart from your mind’s processing of them?”
“No, I guess. Both require a fair bit of mental processing of what’s being sensed.”
“Then why,” asked the kid, “is the straight pencil real and the curved pencil an illusion?”
He shook his head. “It’s different. Illusions are when your mind misinterprets the inputs and as a result incorrectly processes the stimuli. In the case of the curved pencil, it has to do with moving the pencil in a particular sequence of translations while rotating it back and forth near it’s midline between 0 and 90 degrees. Your mind basically misreads all the movements and thinks it’s curved even when it’s straight. Sure in both cases the mind is processing sensory stimuli, but see sometimes it’s processing correctly and sometimes it’s wrong.”
The kid glared at him. “So that’s what you think. One’s wrong and one’s right. Some things are real and somethings are just mind tricks, like ghosts or hallucinations. Well how do you know when you’re being tricked and when you’re not? When’s a thing really a thing?”
“It’s a thing when it makes sense and it isn’t when it doesn’t. Ghosts don’t exist because it doesn’t make sense for them to. There’s no sensible explanation for their existence, but there’s plenty of explanations for how plays of light in the corner of your eye can be processed incorrectly by your mind when you aren’t attending to them properly. Plenty of kids make monsters out of the shadows in their rooms. It’s the same thing with the curved pencil. It’s like I said before. I knew it was really straight because wood is rigid and doesn’t bend easily.”
The kid grabbed the pencil on either end with both of her hands. She turned her wrists bringing both of its ends together so that it formed a circle. “It’s made of rubber you dolt.” With that, she got up and ran straight for the opposite wall before dematerializing into air