Friend, thank you so much for your support and your opinion. I share your opinion, but you know, I wrote about this phrase because sometimes we judge a book's cover without even reading it. Of course, sometimes appearances speak for themselves, and that leads to uncovering liars, murderers, etc., and as you said:

Instinct can tell what fools the eye.

Friend, what you said is very true.

Thanks for the support. That's why I made this post to share it with others and see what they think about this phrase.